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00. Table of Contents

00. Table of Contents (this page)

PREWAR PHASES
01. Initial Planning
02. Rearmament
(A. Massed U-boat Theory)
03. Diplomacy

WAR IN EUROPE
04. Danzig May (1939)
(B. Restriction and Unrestriction, and Surface Warfare)
05. Finisterre June
06. Warsaw July
07. Utrecht August
08. Maastricht September
09. Luxembourg October
10. Baghdad November
11. Amsterdam December
12. Gouda January (1940 begins)
13. Hague February
14. Athens March
15. Leuven April
16. Marseille May
17. Casablanca June
18. Brugge July
19. Darwin August
20. Perpignan September
21. Metz October
22. Aleppo November
23. Strasbourg December
24. Bruxelles January (1941 begins)
25. The Fall of France, February/March/April 1941

26. Epilogue

do0001.jpg


So I figured I'd try my hand at the new standard AAR format, which I don't like very much. Recently I've been reading Clay Blair's Hitler's U-Boat War (Vol.1 Vol.2) (and playing a certain amount of Silent Hunter 3 and Silent Hunter 4). Blair provides a sympathetic but skeptical treatment of Karl Dönitz's prewar plans for naval dominance, which involved mass commerce raiding by a fleet of 300 Type VII submarines. Historically, the Dönitz plan was initially passed over in favor of a more ambitious effort to build a generalist navy; given that Dönitz had counted on extra lead time to build his U-boat fleet, this means his plan never really got a fair shake.

Blair doesn't actually think the Dönitz gambit would have worked. He claims that Allied antisubmarine capabilities were too advanced, that convoying was too useful a defensive strategy, and that the effectiveness of German submarines has been overstated (particularly the Type XXI, but with reliability being a serious issue in general). The hypothetical case involving Dönitz's original plans is speculative, but what's undeniable is that in the actual war as it was fought, submarines were not a decisive factor for the Germans.

Well, this is Hearts of Iron III, land of the hypothetical WWII scenario. My goal in this AAR is to put Dönitz's plan to the test. I will make the submarine commerce war as central to my strategy as I can, and other programs will defer to it whenever possible. Dönitz built his ideas against Britain, so the focus will be on bringing down the United Kingdom and avoiding entanglement with the Soviet Union or United States at least until that's taken care of.

Starting in 1936 means there's no guarantee of historical behavior by other nations. This is fine with me. Like Dönitz, I aim to prepare for the war I expect, but I might have to deal with a two-front war in spite of myself, or discover that Britain is not interested in going to war over Poland and France after all. Only time will tell.
 
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01. INITIAL PLANNING

The game is Hearts of Iron III 2.03c with the Semper Fi expansion. Scenario is Road to War/1936. Selected nation is Germany. Difficulty is normal, game mode is normal. Victory conditions have been selected to avoid the Eastern Front and Japanese involvement, both of which I consider optional. As a result, the emphasis is on control of Europe. I will leave the ground war, and usually the air war (with the Blitz being a major possible exception), to the AI, but I'll shape policy for both as necessary through indirect means, particularly research /production/diplomacy.

VC 01: Operation Sealion. Little idea yet how exactly I'll accomplish this. My plan doesn't call for outright high-seas dominance, so an E-Day in English home waters is probably out. Tentatively, I hope to combine popular unrest from convoy interdiction with military oil shortages that ground the RAF's defense against the unity-lowering London Blitz. Then again, maybe oil shortages will stop their ships from intercepting my invasion fleets. A large-scale paratrooper "Airlion" is probably impractical. Answering the questions posed by this victory condition will likely be the crux of the campaign, and it's what the Dönitz plan was meant to do.

VC 02: Operation Tannenbaum. The conquest of Switzerland. I hope my ground forces will be up to the task. I anticipate difficulties with the terrain, and possibly also with the diplomatic ugliness of attacking Europe's most dedicated neutrals. Tannenbaum may well be delayed until it is the last conquest on the Continent.

VC 03: Italy is an Axis member. I don't have plans to lean on Italy too heavily (I even struck Malta off the VC list), but I wouldn't want Italian territory to be non-Axis and I'd rather not invade (although I will if I must). If things go well, I can protect Italy from whatever might threaten it.

VC 04: Spain is an Axis member. Same basic deal as Italy. The Spanish Civil War, assuming it happens, will be a test case for strangling convoys, and possibly also for air support.

VC 05: Turkey is an Axis member. This might be a bridge too far. I'd rather fight here than in Russia, if it comes to that. Securing Axis Turkey diplomatically would be neat, but I'm not counting on it too heavily.

VC 06: Axis controls Sweden. This might actually be unworkable. In the event that Sweden can't be persuaded into the Axis, it depends on whether I can ferry across the Baltic with impunity, the Finland situation, and how other land wars are going and whether it makes sense to divert significant forces to Sweden.

VC 07: Portugal is an Axis member. If I can get Spain, this is probably no big deal. If I can't, I don't look forward to trying to move land forces there, considering likely British surface dominance in the Atlantic and Mediterranean.

VC 08: Vichy France is an Axis member. If this doesn't happen, I'll be in trouble one way or the other, so I might as well put it in the victory conditions.

VC 09: Axis controls London. Natural consequence of Sealion. All or nothing!

VC 10: Axis controls Paris. Natural consequence of Vichy France.

VC 11: Axis controls the Suez Canal. A peculiar byproduct of my strategic focus is a reliance on the African front, which I see as being much easier if I can successfully interdict Britain. This is kind of a gamble since reinforcement may be difficult. If Africa collapses but everything else goes well, I can perhaps march through Spain and into North Africa via Gibraltar. Another possible vector for overland African movement is Turkey. Lastly, if I really do stomp Britain, the surface power in the Mediterranean may be Italy, allowing me to move transports after all.

VC 12: Axis controls Gibraltar. Natural consequence (I hope) of either Sealion or Spain or Africa.

VC 13: Axis controls Baghdad. Natural consequence (I hope) of either Sealion or Turkey or Africa.

VC 14: Axis controls Ploiesti. If Romania cannot be coaxed into the Axis, I will turn the army loose on it.

VC 15: Axis controls Beograd. Like Romania, Yugoslavia will take membership in the Axis either willingly or by land invasion.

These victory conditions can be condensed into the following War Objectives (in order of importance, not chronology):

do0101.png


WO I: Control of the United Kingdom and all its territories, particularly in North Africa and the Middle East. To be accomplished by combined forces, but particularly submarine commerce raiders at sea and urban bombing by air.

WO II: Control of continental Europe, including France and all its territories (particularly in North Africa), Spain and Portugal (including Gibraltar), Italy, the Low Countries, Austria, Hungary, Czechoslovakia, Lithuania, Latvia, Estonia, Bulgaria, Switzerland, Greece, Romania, Yugoslavia, Albania, and possibly Denmark (particularly continental Denmark). To be accomplished by diplomacy where possible and land invasion otherwise. Islands are not a priority.

WO III: Control of North Africa and parts of the Middle East, including French and British assets (explicitly Iraq, Gibraltar and the Suez Canal) and Turkey. To be accomplished by diplomacy if possible in the case of Turkey, and presumably by a protracted land campaign. Intervention by air, sea, and leveraging other fronts may be necessary. Note that WO II and WO III have some overlap, which will hopefully allow fronts to merge as the war develops.

WO IV: Control of Sweden. The rest of Scandinavia is optional, but hopefully Finland can be drawn into the Axis. Details uncertain. Possible invasion through the Baltic.

WO V: Avoidance of hostilities, at least until everything else is resolved, with the USA and USSR. Defensive preparations on the Eastern Front for a potential holding action. No plans to occupy Persia and Saudi Arabia at this time (but I might reconsider for oil).

do0102.jpg


Okay, so let's do the 01/01/36 routine.

The first order of business is to hit the low-hanging fruit on the technology tree. Submarine research, sadly, is not yet nearly low-hanging enough. (When it becomes available, I would do well to remember that engine research is not a priority because short-range subs will still be useful when based from ports in northern France.) The most pressing stuff in terms of research date and necessity for the war plan is basic infantry, light tank, and strategic bomber research. WO II assumes a very capable land force, and the sooner I can start building it, the better. (I envision infantry as the backbone and substantial numbers of light and medium tanks as spearhead material.) WO I assumes carpet bombing, so I need to be able to do that too.

To do this research, I cut leadership to the officer corps. I can ram officers into the army closer to the time; right now, my officer ratio is around 150% and I'd rather have scholars and engineers. Significant effort is also directed to diplomacy and espionage, both of which will be utterly crucial to the workability of WO II. I do not expect to march on all Europe. Italy is my top priority for Axis recruitment, followed by Romania, Yugoslavia, and Portugal. Finland, Norway, and Turkey are serious possibilities. Spain can go its own way for now, since the Spanish Civil War is coming.

As for espionage, my biggest concerns at the moment are probably France and the home front. I narrow the scope of Germany's intelligence program very, very dramatically.

Priority 3, political espionage: France, United Kingdom, Soviet Union, United States.

Priority 2, support fascism: Italy.

Priority 1, support fascism: Republican Spain, Turkey.

Priority 0: Spies in all other postings have been instructed to promote fascism or conduct political espionage, as appropriate.

Diplomatically, I influence Italy, Romania, Yugoslavia, Austria, and Turkey. Bringing Austria into the Axis will put me closer to the Anschluss. I'll build a couple of brigades to gain eligibility for Reoccupation of the Rhineland.

Production! Pre-existing items in my production queue are as follows:

1. The heavy cruiser Graf Spee, nearly completed. I'm told that despite being limited in size by the postwar naval treaties, it's a marvel of modern engineering. Wrong. Marvels of modern engineering submerge and fire torpedoes. SCRAPPED.

2. A destroyer flotilla. Eh, I won't have many capital ships to screen, and as for ASW, it's not gonna be my convoys out there. (Remind me to prioritize the conquest of Poland so that I don't have to convoy past Danzig by the time the Royal Navy goes hostile.) SCRAPPED.

3. A U-boat flotilla. ... YOU MAY PASS.

Now, I hesitate to suggest that the navy be one hundred percent U-boats, but on the other hand, I know how the story goes with surface fleets. I don't want to burn the supplies to maintain something like the Graf Spee if it's just going to sit locked in a Baltic port for fear of the Royal Navy. And should things get to the point where it doesn't have to fear the Royal Navy, I won't need the Graf Spee. I figure a relatively token escort for transports should be enough, and I'm inclined to look to ships already afloat to handle that. If it comes to it, I might license some surface ship designs from the Italians much later.

Two infantry brigades in the pipe for Reoccupation. I'm leaving the rest of the production untouched for the moment so that I can see what my supply burden is like before committing.

Finally, here is my cabinet:

do0103pol.png


I won't lie, these guys are not ideal. My focus is on general tooling up, so where possible I have selected general bonuses that will assist in research or construction (Goebbels, Schacht, Hess, von Blomberg), but elsewhere I am dissatisfied. Saalwachter is a purely symbolic appointment, of no more actual use than Raeder but a gesture toward desire for change. Beck is not bad, but neither is he immediately useful. Canaris and von Neurath will do. Göring is trash; I badly need an evangelist for strategic bombing in his position, a Curtis LeMay, but none is available.

On second thought I swap out Canaris for Frick. Frick gives an espionage bonus, so between Frick, Hitler, and my precision approach to spycraft, I should be able to see some results.

Next week: I unpause!
 
Thank you for participating in the Writing with the StAARs Competition. I'll be watching an eye on this. I'll also have to pick up the books you mentioned =)
 
I appreciate the interest, fellas. Here's the next update.

02. REARMAMENT

It's September 1937 and the Spanish Civil War has broken out. It is a good time to assess the reconstruction of the German military. So far the diplomatic situation has been tense and unproductive, with no Axis joiners. (Japan is open to it, but refused my first offer, which is probably just as well since Japanese involvement doesn't fit with my strategy. They are currently invading China through Manchuko, and it's fun to watch, but part of the fun is the distance.)

The first order of business, inevitably, is whether we are any closer to achieving WO I, the interdiction of Britain. I've split the armed forces so that nearly the entire army, led by the AI, is dedicated simply to WO II and the European land front as a whole, and a token land detachment in North Germany serves as naval headquarters. Raeder commands a pocket task force anchored by two heavy cruisers and screened by a a mix of light cruisers and destroyers. These surface ships are pre-36, but generally decent, and although I don't see them as a remotely serious challenge to the larger elements of the Royal Navy, I expect them to handle other threats and maybe even defend quick transport operations in the Baltic. They could also be useful for bombarding and blockading Danzig.

The U-boat flotillas are based in Wilhelmshaven for now, but will probably develop better ports later on. There are four commands, each with around six flotillas. All of the commanders (von Nordeck, Assmann, Wolf, and Claasen) have the Sea Wolf trait, which provides a submarine attack bonus. If a U-boat flotilla in HoI3 contains five boats, then we are about forty percent of the way to the Dönitz goal. Nearly all of these flotillas come from a crash building program in 1936 and can be considered improved Type VIIs. There are a handful of IIA and IIB boats still in service.

Claasen, as the least promising commander, has been given three flotillas of Type IIB boats, one flotilla of IIAs, and only a single flotilla of modern VII+s. This limits his wolfpack's range to 500 km, which is still enough to terrorize the Mouth of the Thames. All the other wolfpacks are entirely VII+, with a 1700 km range allowing comfortable operations as far out as Rockall.

U-boat research continues, with improved submarine development starting in 1937 alongside ahead-of-schedule theoretical work. Unrestricted Submarine Warfare is a 1941 tech, but I'd like to have it by 1939. (Historically, one of the German concessions in the interwar naval disarmament treaties was a pledge not to conduct unrestricted submarine warfare, as they briefly and controversially had in WWI. The other aspects of these treaties were mostly about scrapping ships and not building new ones, a concession that takes construction time to reverse, but the Germans could, in theory, have gone full unrestricted again with the speed of an encrypted radio message to the sub fleet. In practice, Hitler was torn by the same reluctances about it as the Kaiser and it took time for the rules of engagement to be lifted. I consider the research time for the Unrestricted Submarine Warfare project to represent the need to repeatedly lobby the leadership for it.)

The actual U-boat models each had strengths and weaknesses. So far as I know, HoI3 does not model the faster dive speed, smaller turn radius, or more elusive size of the little boats, so larger stuff like the Type IX and Type XXI will be just plain better. That having been said, there will always be work for submarines with limited range. If there ever isn't a need to stifle convoys to Britain, France, the USSR, or anything in the Mediterranean, I will have won anyway. Because of this, submarine engine research is not a major priority for me. As long as the engines are reliable, 500 km is enough for some and 1700 km is enough for most. As a contingency, at least some of the fleet should be able to raid the American coast by 1939 or so. I hope that doesn't become necessary.

do0201.png

"No" is kind of a weird value for engines and hulls and torpedoes, isn't it?

The other potential weapon against Britain is the air arm, which is under control of the main army. I have eagerly granted lackluster (skill 1, Logistics Wizard) Field Marshal von Epp's requests for interceptors, but held off on tactical bombers and multi-role fighters. I may potentially use the multi-role fighter to fill the air support role while contributing to air superiority and benefiting from fighter research. The transport plane/strategic bomber side of things is still in its infancy, unfortunately. In the meantime I have ousted worthless Göring for light aircraft specialist Ulrich Grauert. Better a bonus to fighters than nothing, particularly as my air strategy calls for air superiority and reliance on interceptors rather than anti-air.

Naval WO I capability is at least a year away, probably more. Realistically, expectations for effective WO I contribution by air should be deferred indefinitely, although the interceptors built up for the WO II command are a start.

do0202.png

Goddamned land army stealing my submarine fuel.

WO II is on decent footing. I am responding to force requests from von Epp, who has been given massive new infantry formations and a large light armor contingent. He is now primarily requesting motorized infantry and medium armor, both of which I am trying to go a bit easy on given likely fuel constraints later on. I may try to appease him with small numbers of motorized infantry and a broad program of upgrades that outfits existing light armor units with medium tanks. I don't plan to develop heavy armor.

von Epp has a wholly orthodox approach to front designation, choosing to line the Polish and French/Benelux borders while ignoring Austria and Czechoslovakia. This is probably the right way to do it. Ports and major strategic targets are also defended, but I am a little concerned by the broad deployments of light armor opposite northern Poland. Additionally, von Epp could stand to show more initiative in ferrying units east of Danzig. At his request, I have provided him with two transport flotillas for this purpose.

I am hopeful that the diplomatic end of WO II will soon produce results. Italy should be eligible to join the Axis in the near future.

do0203.png

Who needs an armored reserve?

Serious consideration of WO III is a long way off. With no Italian cooperation, no hostilities at sea with Britain, and no immediate prospect of a Turkish alliance, there's just not much to do in Africa or the Middle East. I don't even have any Mediterranean ports.

WO IV is as speculative as ever. There's no particular prospect of roping in Norway or Sweden or Finland or Denmark anytime soon, although the Allies might. I may lose the Estonian corridor option if the Soviets advance. Naval viability relies on too many factors to make a serious guess, but assuming the Eastern Front remains quiet, I think a part-naval invasion of Scandinavia isn't entirely out of the question. The biggest danger, of course, is a British task force beating up my transports and surface ships, and blocking movement in the Skagerrak area.

do0204.png

Could be better. Could be worse. Hello, Italy.

No news is good news on WO V, although I wouldn't mind hearing some diplomatic overtures from the Soviet Union. The USA is unfortunately looking like a contender for the Allies.

Next week: Can submarines help Spain?
 
How do you plan to employ your subs once the shooting starts? I've been experimenting with 1 to 5 size groups. The smaller the groups, the more groups you have, the more ships you can sink. In my (limited) experience, larger groups are only useful when you encounter hostile fleets (in which case you'd want to retreat anyway).
 
(A. MASSED U-BOAT THEORY)

This is the first of several planned appendices outside the weekly format dealing with issues tangential to the overall campaign (and making up for the sparse posting that the weekly format entails). Baltasar raised the important question of how exactly the submarines will be deployed, and in particular whether they will be deployed en masse.

Historically, the submarine force was never deployed in the numbers or concentrations that I intend. In 1939, only 26 U-boats made patrols between the beginning of operations in August and the end of the year. In September 1937, I have over 100 U-boats ready for immediate duty.

Historical U-boat deployments were extremely spread out, with missions to defend Scandinavia from invasion, interdict shipments to Allied forces in North Africa, attack American shipping off the North American coast, patrol west of the British Isles to report inbound weather off the Atlantic for the benefit of the Luftwaffe (!), and even support Japanese operations in the Pacific. I don't rule out the potential for most of these as side operations, but the main focus will always be WO I and the defeat of Britain.

In HoI3 terms, even a single flotilla would be unusually numerous as a concentrated anticonvoy force. U-boats tended to attack alone, and even when coordinating attacks, they would be unlikely to engage simultaneously. This is partly due to the difficulty of intercepting a convoy or task force with a U-boat while remaining undetected (as U-boat top speeds tended to be lower than warship top speeds, especially for submerged U-boats), also partly the difficulty of finding targets at sea (German radar was inferior at best, and scouting by air was largely unsatisfactory), and very critically a justified paranoia about radio transmissions that limited communication with deployed U-boats. (The Allies could often decipher messages to and from U-boats, and whether they could read the signals or not, they used direction-finding equipment to triangulate the positions of submarines making radio broadcasts.)

With these things in mind, there are two branches of U-boat attack theory that I want to pursue. The first is convoy warfare, and it will probably be fairly recognizable to students of the war, particularly in its initial stages. Since a convoy isn't represented in game as an actual unit in the sea, but rather as a route, the way to engage convoys is not through ordering direct movement and attack, but rather by setting up pickets where convoys will travel.

HOME PORT PICKETS are the most basic deployment. In this system, U-boats lurk in waters near British ports and sink traffic as it arrives and departs. There are three major advantages to this system: 1. it requires the coverage of only a small area (permitting concentration and limiting the minimum number of boats needed to be effective), 2. it involves very short operational ranges (even from Wilhelmshaven, the obsolete boats in Claasen's command can participate), and 3. nothing bound for Britain can avoid the blockade entirely. There is also, however, one overwhelming disadvantage: home port pickets will be well within range of British radar warning systems, air patrols, and whatever fleet assets they have in home waters.

MID-OCEAN PICKETS are a little wilier. This method involves a line of U-boats strung through the Atlantic, seeking to detect and converge on convoys. It's something of the opposite of home port pickets. The advantages is that the dangers of British defenses are limited by the vastness and remoteness of the mid-Atlantic (as well as the greater dispersal of boats). The disadvantages are that 1. the U-boats are dispersed, limiting the damage they can do when attempting to converge on located convoys (historically, the boats would often scramble and not make it in time to catch the convoy, and it was also a bad occasion for dangerous radio traffic), 2. the U-boats are unlikely to cover the entire area, allowing some convoys to slip through, and 3. moderate range capability is required, ruling out (in my case) Claasen's boats (although France could change that). The nature of the mid-ocean picket changes depending on how near the coast the boats dare to set up. Boats on weather-reporting duty (both U-boats and trawlers) functioned as a mid-ocean picket in the real war, but the frequent radio communication required for weather reporting interfered with their effectiveness in that role (and made them targets for British operations to capture German encryption materials and devices, worsening the problem).

FOREIGN PORT PICKETS are a more daring option which potentially combines several drawbacks. A foreign port picket pulls the home port picket routine, but overseas. This would absolutely require extreme-range boats and could potentially be just as dangerous as patrolling the Thames, depending on the local ASW capability. The United States is the logical target if necessary, but if they don't have Japan drawing off part of their navy and air force to the Pacific, I'd be skeptical of the overall utility of the gambit. (For this reason, if America declares war on me I will try to bring Japan into the Axis.) Also, the foreign port picket will only intercept traffic from that port, and not all the traffic involving the British Isles. A mass foreign port operation is probably only worthwhile in the case of the USA entering the war. Minor foreign port pickets might be useful in lightly-defended areas such as South Africa or South America, but advantageous bases (via Spain, perhaps?) would be crucial, and that's in addition to extreme range capabilities that I simply don't have currently and am not sure I can afford to prioritize.

KNOWN POINT PICKETS would be large clumps of boats staking out established convoy routes in the middle of the ocean. Without clear intelligence on the convoys, this would be an all-or-nothing maneuver, as a bad location would tie up an entire operational group and produce no results. There's also the danger of a massive, organized ASW response. This concept is an experimental one.

doa01.png

From Silent Hunter III, map detail of convoys and air cover in the vicinity of Britain. Note grid reference system; this means of designating locations was intended by the Germans as a layer of encryption (as opposed to the internationally recognized latitude/longitude system).

The second branch is, of course, attacks on task forces. These specifically tactical ideas are impossible to implement directly in HoI3, but I intend for them to demonstrate that mass U-boat operations against large groups of warships are not unthinkable.

FLAYING is a standard operational procedure for lone U-boats encountering task forces. In the absence of a good shot at a capital ship (likely because of screening), lone boats should attack screening ships (primarily destroyers) and then escape. The more screens are sunk, the better the subsequent chance of a U-boat or mass of U-boats eliminating the central elements of the task force.

HORSESHOE is a task force attack pattern involving a significant contingent of U-minelayers (at least six). These minelayers are directed to the path of a task force, where on short notice they lay prearranged minefield segments that form a horseshoe shape intercepting the enemy warships. The "bottom" of the horseshoe, directly in front of the taskforce, should be deep enough to convince survivors to divert course, whereupon they will strike the mines on the sides. Encountering mines seemingly in all directions, the remains of the task force may even consider themselves stranded. (The rear can be mined lightly as naval groups don't like to backtrack from their intended destination, particularly once indoctrinated withzigzagging ASW techniques.) The minelayers might also reserve the option to loiter around the field and add some torpedoes to the festivities (Allied crews might even mistake wakeless G7e torpedo attacks for further mines). U-minelayers were real historical boats, but they mostly mined ports, where mines are expected (and quickly charted and swept) and sinkings are shallow. (Many ships sunk in port were simply raised and returned to service.) A hasty minefield on demand in deep water would be extremely dangerous. German mines had twice the explosive of German torpedoes, and exploded beneath ships to directly damage keels (like the most damaging torpedo shots). This kind of attrition could seriously cripple the Royal Navy. A major drawback to this tactic, though, is that it leaves an unreported minefield in the ocean where German forces may blunder into it. (It wouldn't be radio-safe for the U-minelayers to indicate the field.) This is, however, something for naval command to plan around, hitting task forces when they're off normal U-boat sealanes. Once the minelayers reach port, information on the minefield can be distributed.

doa02.png

The roles of different minelaying boats in a five-boat horseshoe. Depending on the reliability of information about the target and the steadiness of the target's course, the horseshoe could be "shallowed out" for greater uncertainty, with the flotilla arranging a wider pattern by rendezvous and the middle three turning their patterns sideways.

THORN DANCE is a task force attack pattern involving around 30 standard, torped-capable U-boats. A single, deeply coded and seemingly innocuous signal from headquarters indicates a time and place at which a task force will be attacked. Each boat lines up on a prearranged, boat-specific heading from the central location, roughly 1500 yards from where the fringe of the task force (hopefully attritted through flaying, allowing close proximity to the capital ships) is expected to be at that time. Via surface maneuvering and hydrophones, boats can position themselves relative to each other. Each U-boat lurks at a deep depth (certainly deep enough for the task force to pass over) until the task force (detected via hydrophones) has progressed to the center of the formation. At this point, the subs rise to periscope depth, line up their best shots with a slight (though not wholly decisive) preference for ASW-capable ships, and fire narrow salvos (perhaps with about 2 degrees between torpedoes) from all fore tubes. The torpedoes are set for shallow run depths (e.g., 1 meter) and contact explosion, meaning that they are unlikely to strike U-boats on the opposite side of the task force. The U-boats then descend to predetermined depths, interleaved among adjacent boats to minimize the risk of an underwater collision (or depth-set depth charges), and reverse course, initially by backing and then by turning around. In the event of active pursuit from convoy survivors, U-boats should carefully target shots from their rear tubes (rising to periscope depth if necessary), or possibly fire homing torpedoes (although this would require all U-boats involved to run quiet for safety reasons while escaping). (As of September 1937, I already have the Zaukönig I homing torpedo researched.)

doa03.png

I have a feeling practical considerations might make a mess of this, but it's worth trying.

FIRING SQUAD is a simplified Thorn Dance intended for smaller groups, and something that can potentially be put together on the fly, possibly by a surface rendezvous in which captains shout back and forth by megaphone (the British are less likely to be able to eavesdrop on this unless they have built a giant hearing trumpet in Cornwall) or flash terse one-time pad morse code at each other with topside lights (these are both good general interboat communication methods for any of these operations if such communication becomes truly necessary). A handful of subs take up positions around a spot the task force is expected to cross, attack together following the lead boat's attack, then support each other's escapes. This is compatible with some degree of minelaying, and the initial signal might be the task force striking the mines, rather than a torpedo shot. Bluntly, Firing Squad is a somewhat recognizable take on the coordinated wolfpack.

A disinformation campaign about secret weapons will be conducted, focusing on creating the impression that new torpedo types and capabilities exist, including externally-stored torpedoes which seem to be capable of direct launch, torpedoes which deploy decoys at a set distance (which may or may not be worth developing for real), markings on torpedoes and new design features which appear to allow a new modular component (that does not exist) to be inserted into the torpedo, and a number of torpedoes marked with a purple nose stripe that crews are simply told is "top secret" (to hopefully confuse the Zaukönig issue, as it would be trivial to develop countermeasures (i.e., over-the-side noisemakers, or even depth charge patterns to confuse the torpedo) for acoustic tracking if it were understood; this is what happened historically). Early deployments of Thorn Dance and Horseshoe are ideally going to result in chaos and confusion on the Allied side, and that can be exploited to stifle the development of countermeasures. I'd rather they were afraid of an imaginary supertorpedo than methodically planning ways to handle what's really going on.

All of this hinges on secrecy and undetectability. Mass attacks should probably not be conducted near the British coast, in order to avoid air patrols and land radar. Encryption research would do a world of good (and decryption research would help too, for targetfinding). Serious precautions should be taken to keep the content of radio messages concerning these operations impenetrable, and to relieve U-boats at sea of the need to send any preparatory signals at all.

EMPTY EYES is a new set of naval communication standards applying only to U-boats and primarily to massed attacks. In general, U-boat orders are issued when the fleet sails and not updated, and U-boats are strongly discouraged from broadcasting status reports (which are strictly forbidden if the fleet has been sent out to attack a task force or mass in a known mid-ocean convoy point). Aborts in particular are to be done silently, as if one boat is aborting from something, there will be other boats in the area. Only designated scout boats will radio contact reports, and they will attempt to do it a significant distance from other submarines. U-boats will not identify themselves by radio unless it is for some reason necessary. Another sensible thing to do would be to detail a couple of flotillas to run around the North Atlantic sending bogus signals in U-boat naval Enigma, with corresponding traffic from headquarters. Real boats will know these messages are false because they'll be in disused keys (the primary seed for Enigma encrypt-decrypt is a three-letter code).

Most of all, orders to fleets engaged in Horseshoe, Thorn Dance, or Firing Squad operations must be short, simple, and utterly opaque. To that end, as many of the associated details as possible are prearranged with the captains. Only the captains, the fleet commanders, and the relevant admirals know anything at all about these plans, which are only written down in a single secure place: tattoos on Assmann's back. (Assmann is forbidden to sunbathe before the end of the war.) With so much vital information entrusted only to captains, boats on special assignment are instructed to return to base if the captain is killed or incapacitated rather than risk them fouling up an organized action with independent operation (such as blundering into a Horseshoe).

INFORMATION PROVIDED TO DEPARTING U-BOATS
* explained to captains in port
... fleet composition
... general patrol zone
... local patrol zone (different for each boat)
... which boats are designated contact reporters
... contingency rendezvous signals and points, non-radio wherever possible
... for Horseshoe, the boat's designated minelaying pattern
... for Thorn Dance, the boat's designated heading and depth preference
... two points which designate a line used to further encrypt positional information
... secret radio protocols for identifying a camouflaged attack order
* distributed to radio officers
... this-operation-only contingency signals (on water-soluble paper)
... standard encryption/decryption (i.e., Enigma materials and devices)
* explained to crew
... nothing

The signal initiating an interception and attack has to be completely secure and not rouse any suspicions. Therefore, not only is no response given to it, but it is also disguised as a routine order to a lone boat in a different area. The nature of the order and the boat are explained to the relevant captains, but not to the decoy boat itself, which should faithfully carry out the dummy order as normal. The coordinates of the order given to the decoy can be reflected over the secret plotting line given to the captains participating in the attack in order to reveal the location of the ambush.

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An example of a double-meaning order giving an encrypted intercept point. Further refinements could include time information in the hidden message as well as indicate the target's own heading. Minelayers are particularly good fodder for this ruse because it is common sense that laying a minefield would be the subject of relatively dense radio traffic involving precise locations, and an enemy force doesn't need to be in the area at the same time to make it plausible.

Cybvep, essentially the entire army is under the command of von Epp, whose headquarters has both AI Control and AI Reorganization enabled. I will probably leave it that way for the most part. I reserve the right to break off formations for operations outside of the primary WO II framework, particularly should I have the need or opportunity to reinforce the Italians in North Africa. Nearer to the present, I may directly (or via a finer grain of AI control) control a contingent assisting Nationalist Spain, and more speculatively, I may do Sealion myself. If worst comes to worst and we find ourselves at war with the USSR, I plan to split that off into a separate AI-controlled command so that von Epp doesn't have to worry about it and I can more precisely allocate forces to that front.
 
I would like to point out, in case you don't already know, some of the common convoy routes as per my Germany AAR. The Northern Azores and the Coast of Cadiz are the richest hunting grounds possible, as more traffic flows through those two sea zones than any other, with the exception of the heavily-patrolled Approach to the English Channel. The Celtic Shelf, the Saharan Coast, and the Coast of Galicia are the next-best targets. Aside from that, any sea zone near western Africa and northern Spain will have a lot of convoys going through them. If you can get convoy raiders near Newfoundland, then you can intercept any convoy going to or from North America.

Since I'm using a mod for my AAR, I don't know if vanilla's subs can reach these areas, but if you can manage to do so, you'll inflict crippling convoy losses on the Allies. Also, don't forget that submarines make great scouts when trying to find a weakness in the UK's patrols and port garrisons when performing Sealion.
 
Oh My God! Your attention to detail to extremely impressive; I can see that you have taken your time and effort in producing a as-historical as possible update.
 
this is really impressive - really like the detail and approach and its so nice to find a different style of German AAR. Given that I've rather fallen in love with subs (by accident not design) in my current game, it'll be great to see what you manage by intent.
 
03. DIPLOMACY

The Axis is growing at the negotiating table. Old lines are being drawn anew. As of May 1939, I am about to demand Danzig from Poland. Poland went Allied when I took Czechoslovakia. I have yet to bring in Turkey, Portugal, Nationalist Spain, or any of Scandinavia.

Other than that, things seem to be going okay. I took Austria, Czechoslovakia, Memel. Got the Molotov-Ribbentrop pact (in January of 1939). The Nationalists are proving difficult to woo, but at least they won despite the mess of the war. (More on that later.) I used Spain as an excuse to shift to the total war laws. Resigned myself to the USA staying in the Allied corner and probably joining the war; got Japan into the Axis as a counterbalance. (Nationalist China and Xibei San Ma have been swallowed.)

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They fight to keep Spain neutral, I fight to keep Ireland neutral. I can see Irish neutrality being modestly inconvenient for the UK come war convoy time. The main show here, of course, is the gentle but firm removal of Scandinavia from Allied influence. But look how many unaligned countries are starting to see which way the wind is blowing, too. (NB: Most of these are filtered for just Europe, but there's one in the middle with everything.)

Diplomacy has been weird and tense and a huge drain on my Leadership. My bottom line for it has been WO II. (WO V is probably a wash, as it looks like I'm going to be stuck with historical American involvement, the historical Pacific theater (with no victory conditions for it, mind you), and having made the Molotov-Ribbentrop pact, I worry that the Soviets will conduct their own Barbarossa.) Although I've drawn many countries into the Axis, there's a lot of unfinished business, and I hope that the war is going to push the fence-sitters onto my side and not into the Allies. Overall, WO II looks a hell of a lot better than it did as a blank slate, and the immediate concern is going to boil down to France and Poland and the Low Countries, and then to deterring the Soviets, sealing my diplomatic deals where I can, and the possible invasions of some minors (particularly Switzerland and Romania).

What little can be seen of WO III at the moment is bolstered by Italy, but not as bolstered as it could be given the lack of alliances with Turkey and Spain. WO IV is the object of a major diplomatic push to bring all of Scandinavia into the Axis as peacefully as possible. Romania and Portugal continue to resist Axis integration, despite being eligible for it. The Balkans, at least, are a load off my mind for the most part. Obviously France and Poland must be conquered, and Tannenbaum is shaping up to be necessary.

WO IV prospects are currently a stalemate, but I have high hopes for continued Axis drift. At the very least, I expect to keep Scandinavia neutral during the bulk of the war, meaning that any Baltic invasion can occur on my own timetable (barring Soviet Barbarossa). There's also a critical effect on the convoy front: bases in Greenland and Iceland, historically vital to trans-Atlantic shipping (Iceland was used as a core escort base), won't be available to the Allies. This has extremely pleasant implications for mid-ocean pickets hoping to operate with a minimum of Allied naval and air ASW coverage.

I have two victory conditions out of fifteen (Yugoslavia and Italy). The road ahead is long.

do0302.png

Objectives in Europe, 1939.

But you're here to hear about the U-boats. Apparently I wasn't clear enough before, but my intent is to operate in extreme concentration (which is to say, generally six-flotilla units of thirty boats), starting in home waters and particularly the English Channel and relying on air power to support me (especially to keep ASW aircraft from taking too great a toll in the Channel). I've begun developing naval bombers that I intend to evolve into a torpedo force to sting or deter the Royal Navy, hopefully keeping them away from whatever ports my subs are basing from. (Pity there doesn't seem to be any synergy between sub torpedoes and air torpedoes.) If resistance proves too tough, I will disperse U-boats into the Atlantic as mid-ocean pickets of one flotilla, but probably converge once I pinpoint good hunting. (The main thing that could make me change up and go more dispersed is discovering that large wolfpacks can't adequately evade air assets and surface task forces. If I have to, I have enough acceptable naval leaders to seriously fragment things.)

Naval research continues, with submarine tactics being important enough to research well in advance of the clock. It doesn't look like Unrestricted Submarine Warfare will be ready when the time comes, but it'll be a much-needed boost when I get it. I have around 240 submarines active now, with about 50 more on the way soon. My latest models are Type IXs, and while the new America situation means I can't neglect engines after all, I am confident that there will always be work for my large stockpile of Type VIIs, perhaps even without French ports.

The Type IXs have long enough ranges that basing isn't critical, so I've split the wolfpacks up to ease the strain on naval base supply patterns (particularly at Wilhelmshaven, which would be my only active base if logistics were no concern). Every development in the war will bring a new perspective to range issues, but for now, I expect the initial convoy struggle will take place right around the British Isles, and I'm more than capable of projecting force there.

Current naval groups are as follows:

von Nordeck WP - von Nordeck is my most promising U-boat leader. His six Type VII flotillas, currently based in Kiel, have performed extended patrols off the coast of Iberia and will be first into the fray should Britain declare war.

Wolf WP - Wolf is another commander with, appropriately enough, the Sea Wolf trait that gives a bonus to U-boat attacks. (The others are von Nordeck, Claasen, and Assmann.) His wolfpack is six mixed VII/IX flotillas, stationed in Wilhelmshaven. I will likely throw him into the Irish Sea to hit Liverpool convoys.

Kiel WP 1 - Saalwächter personally overseeing 12 Type IX flotillas. This is a largely administrative unit and I may break it up, but Saalwächter is a surprisingly capable commander at this level. (Perhaps I should demote him and see if his skill goes up.) He was a U-boat man himself back in the day. Stationed, as you might guess, in Kiel.

Channel Ducks - Commanded by Fuchs, this unit houses the four obsolete Type II flotillas, destined for short-range Mouth of the Thames duty. "Ducks" was a slang term for the Type IIs, which weren't true fleet boats but rather coastal mini-subs, in some ways (particularly range) inferior even to Great War submarines like the Allied S-boats (still in American service in Asia). (S-boats and comparable craft had their own derogatory nickname: "pigboats.") Because ducks have such short legs, it is of course absolutely necessary to base this fleet at Wilhelmshaven.

Assmann WP - The venerable Sea Wolf Assmann now commands six Type VII flotillas from Kiel. He is awaiting new Type IXs and probably an assignment to a more rearward port (Rostock, Stettin, Memel, etc.).

Claasen WP - Another Sea Wolf founder, Claasen's command has been outfitted with Type IXs and based in Lübeck.

Marschall WP - A new command under Marschall in Wilhelmshaven, stocked with VIIs (Claasen's former VIIs, I think).

Deutschland Task Force - Raeder continues to control the renamed stub surface navy. Based in Rostock.

Baltic Ferry - Three transport flotillas on loan to the land forces. Stationed in Stettin, out of harm's way. The only real immediate need for them has been bringing reinforcements past Danzig (and an abortive expedition to Spain).

yet to come - I have about 50 more boats in production. Being Type IXs, they will probably be deployed in ports other than Wilhelmshaven and Kiel. I will try to keep my Sea Wolves in charge of cutting-edge boats, phasing the Type VIIs over to new blood in the command structure.

do0303.png

New boats, new ideas, new expertise.

As for other military preparations, I swapped out von Epp for Rommel, but Rommel wants the same forces von Epp did. I have built out the infantry, provided a handful of motorized infantry units for spearheads, and broadly upgraded the light armor to medium armor. In addition, I have provided a substantial air arm to the land headquarters, and it continues to grow. New initiatives to develop naval and strategic bombing capabilities will hopefully bear fruit in time to be useful. (I think I will even grudgingly give in to the repeated demands for multi-role fighters.) A number of radar stations are under construction, particularly in Wilhelmshaven to watch over the ocean and in Bitburg to coordinate air superiority against the French when the time comes.

do0304.png

This is what the SCW looked like for most of its lifespan, but with quivering borders.

My inept bungles with Spain deserve fuller attention. What happened was this: shortly after Spain declared war on itself, I accepted the German Intervention event and sent three six-flotilla wolfpacks down to the Basque coast to menace the only Republican port in range. This port was promptly taken by the Nationalists. I then deployed the wolfpacks to the Finisterre area for convoy raiding, hoping that the Republicans had trade deals with Britain or somebody flowing to their ports in the south. I couldn't stake out Gibraltar, much as I wanted to, because at the time my longest-range boats were Type VII+ and my nearest port was Wilhelmshaven.

After a while I started wondering why nothing was happening and discovered that I wasn't actually at war with the Republicans or allied with the Nationalists. Apparently my aid was purely advisory. I was unable to declare war or invite the Nationalists into the Axis. I got to work on both, but for the time being I was left holding my dick and stubbornly calling the toothless blockade of Finisterre a "training exercise."

The Nationalists generally had the edge, and they steadily claimed more territory, but at about the halfway mark things bogged down. Madrid changed hands several times. Finally I was able to declare war, and I patted myself on the back for not being too late to score brownie points toward future Axis membership for Spain, although the declaration was pretty token. Then Italy rolled onto the coast around Valencia and took a chomp of Iberia just before the Republicans collapsed. The diplomatic repercussions of this made my friendship with the Nationalists tenuous enough that the Allies continue to successfully disrupt an Axis pact with Spain. I would have been much better off not declaring war. In the end it only took about a year, so maybe a less war-torn Spain than the historical one will be readier to join the Axis.

There's one more footnote to all that. When war broke out in Spain, I threw together a small group of infantry divisions from the land army and placed them under control of the navy. I named their unit "Our Spaniards" out of foreign patriotic feeling (I assume such a unit in real life would be made up of volunteers) and prepared them to voyage with Raeder's surface navy to Andalucia. When their hour failed to materialize, I parked them indefinitely in Wilhelmshaven, and when it became clear that Spain would not soon join the Axis, I petulantly renamed them "Hope of Scandinavia" (after yet another diplomatic hot zone that wasn't yet a lost cause) and gave them back to von Epp.

TheBromgrev, I'll bear your patrol area suggestions in mind. Newfoundland was historically a good hunting ground for American convoys. I am prepared to consider sideshow operations with Type IXs or better off the coast of Africa. I fully expect the waters off Ireland to be key to the blockade. As for the dangers of the Channel, I intend to spit in their teeth, especially early on when I anticipate the British will still be finding their ASW sea legs. I didn't build all these U-boats to shy away from the Approaches. I want to slam a cork in the Channel so tight the Thames dries up.
 
04. DANZIG MAY

Danzig or war resulted, decisively, in war. The full Allies honored the call. This includes Poland, France, the UK, and very unfortunately, the United States. It also includes Belgium, the Netherlands, and Luxembourg, which I declared war on myself to give Rommel the option of the historical attack against France. I should have spent more time influencing the United States just as a spoiling action.

do0401.gif

Top to bottom: overall situation, detail of eastern front with Poland, detail of western front with France and Low Countries.

The war on land is going poorly. Advances are being made in Poland but there's yet to be a massive breakthrough and the Polish forces are keeping up a tough defense. In the west, I'm actually seeing modest but alarming Allied advances, primarily by the French, but even the Dutch are pushing back. Rommel has presented me with a massive new set of force requests that seem to increase daily. Hungary has been asked to open a second front with Poland. Less hopefully, Italy has been asked to open a second front with France. The results so far are unimpressive.

There is no Molotov-Ribbentrop, so the Soviet Union could strike at any time, which complicates an already convoluted race against the clock. Poland must fall in time for the eastern front to send significant force west to bolster the war with France, but France and the Low Countries must fall in time for the western front to reinforce east and deter the Soviets. Hanging over it all is the coming American intervention; in addition to everything else, I have to worry about an early D-day.

do0402.png

Assorted war trivia. (Check out those force requests. No, Rommel, I'm not building you a surface navy.)

I have bad U-boat news as well. Five entire flotillas have been lost in the Channel Approaches to British cruisers. But let me start from the beginning...

The Danzig deployments, May 3rd 1939:

- Wolf to the Channel Approaches. Six flotillas of mixed VII and IX boats, based out of Wilhelmshaven.

- Fuchs to the Mouth of the Thames. Six flotillas of mixed IIA, IIB, and VII boats, based out of Wilhelmshaven.

- Marschall to the Bay of Biscay, intended to disrupt French shipping if possible. Six flotillas of Type VII boats, based out of Wilhelmshaven.

- Claasen to the north of Ireland. Six flotillas of Type IX boats, based out of Lübeck.

- Assmann to the Mouth of the Tyne. Six flotillas of Type VII boats, based out of Kiel. Going ass to mouth might be a bad idea since I'm not sure what convoys I'll hit this way, but historically the Baymans Hole area was a rich hunting ground.

- von Nordeck to the south of Ireland. Six flotillas of Type VII boats, based out of Kiel.

- Dönitz himself (newly available, skill 5 with Sea Wolf) to Skagerrack, expected with a reasonable degree of confidence to disrupt Polish shipping. Six flotillas of Type IX boats, based out of Kiel.

- Saalwächter to Moray Firth. Six flotillas of Type IX boats, based out of Kiel. (Yes, I have split up his previous command. Dönitz got half.)

* By May 14th, Wolf's force had sustained significant damage in the Channel Approaches area, I believe from a combination of air and sea ASW patrols and engagement with escorts, and was cycled back to base for rest and repairs. von Nordeck was ordered to take up his station. Claasen, suffering minor damage and disorganization, has been pulled back temporarily as well.

So what did these convoy-raiding patrols manage to do? Unfortunately, HoI3 has no consolidated convoy warfare report, so I've pieced this together myself from popup data and the naval map mode:

do0403.png

The month of May. Dark red circles indicate proportional merchant kills. Stars indicate escort kills. von Nordeck possibly deserves as much as half of Wolf's bag since he took over Wolf's operational zone around the middle of the month. Bottom: overseas ports around the world whose convoys have been struck in May.

In addition to the merchant convoys, U-boats sank some kind of Dutch flotilla, but the Ships Sunk list has at various times listed it as a flotilla of transports and a flotilla of destroyers. It also has no name. This is mysterious and quite possibly a bug. The historical thing to do, given dubious overclaims by skippers and deliberate inflation of U-boat results by propagandists, is to declare that German vessels have sunk a Dutch aircraft carrier with the loss of its full complement of elves and dinosaurs.

But the bad news is that this didn't come without a price. Losses were acceptable until the end of the month, when a substantial British patrol fleet engaged von Nordeck in the Channel Approaches. In a sustained action, British cruisers sank five of his six Type VII flotillas. This kind of loss is nothing short of horrifying. von Nordeck's remaining boats have been ordered to run scared for Wilhelmshaven, and the von Nordeck disaster will prompt the shift in tactics that I was afraid was coming: a move toward splintered, independent battle units operating at greater distances from the British Isles. What makes this development especially painful is that as yet, I have captured no new naval bases in Western Europe. Historically, the use of Brest as a submarine port was vital to this kind of deployment.

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Sacrifices and setbacks at sea.

My diplomacy and research have taken the lion's share of Leadership, leaving espionage understaffed. In combination with foreign counterespionage, my spy network has been almost completely eradicated in recent years. As a result, I can only guess at what effect the commerce war is having on Allied national unity. Sadly, what indicators there are suggest it is negligible. However, Rommel appears to be conducting strategic bombing in France, with modest but welcome results.

Lastly, here's some data mining I did for convoy sinkings in the month of May.

Total enemy losses: 100 merchants, 8 escorts. HoI3 merchant assets seem to be measured only in flotillas. I'm not sure how to compare flotillas to the historical metrics of tonnage and ships, but my rough estimate is that one HoI3 merchant transport unit equals seven ships which displace a combined 50,000 tons. To avoid confusion with (troop) transport flotillas, I will try to refer to these specifically as merchants. And remember that for now, these are the results of restricted submarine warfare.

This would mean that in May, U-boats accounted for an astounding five million tons of Allied merchant shipping. If that's accurate, I'm not doing so badly despite von Nordeck's losses. In their first partial month of operation, from August 19th, historical U-boats sunk (by my very rough generous estimate) 160,000 tons of shipping with 19 boats on patrol. I'll triple this total to more closely approximate my situation (U-boats set sail on May 3rd): 480,000. With about 240 boats patrolling, I have roughly 13 times historical force. 480k times 13 is 6.25 million. In other words, speculatively, my focus on U-boats has resulted in an increase in effectiveness consistent with linear returns. It's too early to really tell, but this could possibly work.

Losses by nation:
Netherlands: 56 merchants, 8 escorts.
United Kingdom: 26 merchants.
Poland: 8 merchants (Danzig has since fallen, leaving the Poles without a port).
France: 6 merchants.
Australia: 3 merchants.
Belgium: 1 merchant.

I think the Dutch may be losing their entire merchant fleet here. It won't matter much since I intend to conquer them on land anyway, but it bodes well for the real campaign against the British, as do British losses themselves.

Losses by European port:
Amsterdam: 45 merchants, 5 escorts.
Dover: 23 merchants.
Den Haag: 13 merchants, 3 escorts.
Danzig: 8 merchants.
Bayonne: 6 merchants.
Plymouth: 2 merchants.
Portsmouth: 2 merchants.
Brugge: 1 merchant.

Hardest-hit foreign port: Paramaribo, for 10 merchants and 3 escorts. The Dutch East Indies are definitely seeing the heaviest losses of any overseas ports.

Deadliest sea zone: The Mouth of the Thames, for an incredible 22 merchants and 4 escorts, done by Fuchs and his amazing Channel ducks. Bear in mind when you consider the success there that Fuchs is working with a flotilla of IIAs, three flotillas of IIBs, and two flotillas of VIIs. His U-boat losses have been minimal. Holland is Fuched.

But all that aside, the shattering is coming. I imagine a dispersed picket line stretching from Greenland to Iberia or Africa. On the back of the envelope, a patrol density that makes some degree sense in real life (one boat per 20 miles, giving each boat responsibility for detection in a 10 mile radius, which seems like ample coverage for sonar or effective, historical-Allied-level radar) works out to something like two flotillas per sea zone and is within the scope of my current fleet. I may retain an intermittent presence in nearer waters, particularly until I get some westward ports.
 
The unnamed transport and flotilla is a vanilla bug. What those really are, are the last convoy and escorts to be sunk worldwide. If you check your individual subs, if they've sunk nothing but convoys and escorts, you can see exactly how many in their sunk ships view.

The US joining this early is really bad news. While you were preparing to only fight the RN and MN, you now need to deal with the USN and its mighty carrier fleet as well. In my AAR, the only subs I've lost were due to CAGs performing CAG duty; no proper battle was fought, as the RN surface ships themselves never found my subs.