Naval Intel?

[SacremPyrobolum]

I've played in the Pacific many times, but my understanding of it is still crude to the point where all I really do is order my CV fleets to interdict around a large area of sea and wait until I feel they've sunk enough ships to begin landing operations safely. What is annoying is that this actually works and I don't know why. My CV fleet is somehow able to sortie from its base to attack some fleet hidden by the fog of war I can't see.

How did they detect them? It feels like I'm always just sending out my ships into the dark even with radar while my commanders all know something I don't. Its frustrating.

Would creating patrol fleets and assigning them to cruise around large areas let me actually see what is going on and improve interdiction efficiency? Something like 3 CVL, 3DD?

 

[Altruist]

How did they detect them?

Detection is a contest between "sea detection" and "visibility". Both numbers are shown within the ship data:

Japanese BB: visibility 95, sea detection 5
CVL: visibility 80, sea detection 7

Assuming both are accommpied by a DD, chances for the CVL-fleet to detect the BB-fleet are higher than the other way around. BBs are more visible and have a smaller detection chance.

But the Pacific is the by far hugest area on the whole globe. Chances to find a few ships are rather small. There surely is also a strong randomizing factor to simulate historic realities.

Would creating patrol fleets and assigning them to cruise around large areas let me actually see what is going on and improve interdiction efficiency? Something like 3 CVL, 3DD?

I am curious, if you haven't used your own suggesttion, how have you done do it so far?

cruise around large areas

Well, obviously the smaller the area, the higher your chance to find a fleet. So it pays off to think a bit about obvious chokepoints, often called straits, canals or capes:
# Suez- and Panama Canal
# Straits like the Malacca Strait (Singapore), Gibraltar...
# Cape of Good Hope...

Spoiler: Sea- and Traderoutes Indian Ocean

The Sea is such a big place that I usually don't even bother with all the other areas and concentrate on this choke-points... plus the immediate areas of planned landings. Other than that I trust into the AI having much less problems finding my ships than vice versa, thus I escort all my transports and landings and expect battles to come and, given enough time, they usually do.

 

[Eugenioso]

All naval and air units have different naval spotting values, which are different from sub spotting values. The effect is cummulative; ergo, the more ships you have, the more spotting value you have. Individual ships have a chance of spotting other individual ships, but this would be very hard if they're an older model or they dont have radar addons.

Surface ships can be spotted quite well by airplanes, which is why naval bombing is so massively OP: naval units do not have good air defense, except CV's and CL's. This is another problem with the HOI2 engine, CV's dont actually have airplanes, they only have a CAG which counts as a stat increase. Until you spot a fleet you will not see the fleet, this is WAD. This is why its important to have some form of air or naval reconnaissance at all times when doing coastal defense.

Having a small fleet of 3cvl and 3dd is going to mean one thing: 6 ships dead. I prefer my approach to naval war: CV/DD combo and 18 DD fleets with ASW.

 

[SacremPyrobolum]

I am curious, if you haven't used your own suggesttion, how have you done do it so far?

Just set the carrier fleet to interdict and it sorties on its own, able to intercept fleets I can't see myself.

 

[SacremPyrobolum]

Does naval 'spotting' happen only in the sea tile the fleet is located in or does it have a radious?

 

[VTs]

Only the current province.

 

[Altruist]

Having a small fleet of 3cvl and 3dd is going to mean one thing: 6 ships dead.

Depends... as a matter of fact even very much. If you meet a superiour carrier fleet, yes. But against any other fleet composition, 3 CVL/DD are fine and I use them quite often and successfully, especially for general interdiction.

There is also a reason why 3 CVL/DD are sometimes even better than a full 18 ship fleet:
Each ship adds its visibility, so a fleet of 18 ships is highly visible and can be much easier detected. This leads to the enemy fleet having quite a good chance to initiate the seabattle which goes along with a bonus that the battle will be started at the prefered combat distance of the enemy admiral. If he leads BBs those might very well be then in position to shoot at your carriers, bad.

3 CVL/DD are sneakier than the usual enemy BB-fleet but with better sea detection. Thus the chance that the battle is started well out of distance of the BBs and in favour of your CVLs is rather high, good.

It is an intersting trade-off: size of fleet and detection/visibility vs the fleet power of many ships.

If I am certain of a big enemy fleet, I just combine 2 fleets. Or rather, what I nowadays do, I do NOT combine them but I have 2 fleets of 3 CVL/DD operating within the same sea region. While I am not sure wether the DH code really works this way, my guess would be, that with 2 fleets the chance to find the enemy is considerably higher but NOT equally vice versa: 2 fleets each with lower visibility are more difficult to spot than one huge one (quite accurate to reality). And as soon as battle is initiated, all ships within the sea region = both my CVL-fleets take automatically part in it (not very realistic).

See also: Operational Naval Warfare: Mechnics of Seabattles, Amphibious Landings

 

[Altruist]

I am curious, if you haven't used your own suggesttion, how have you done do it so far?

Just set the carrier fleet to interdict and it sorties on its own, able to intercept fleets I can't see myself.

Aah, that's just a misunderstanding on your side about sea battles in DH. Your fleets do the spotting and if they find a fleet it is shown on the map... when it is a friendly or neutral one otherwise combat is immediatly initiated.

With this DH tries to emulate one of the biggest problems and difficulties of historic sea warfare: finding the enemy. All the big historic sea battles were riddled by chance and spotting or not spotting the enemy, sometimes also how to interprete incomplete data like only one warship was spotted:
# Could be part of the big fleet just behind the horizon which your scout couldn't see and thus it is prudent to send out all your carrier planes.
# Could be also a single operating scout-ship looking for your own fleet and the main fleet is somewhere else...
Whole battles were won and lost on what the admiral decided in such a situation...

In DH after combat you can still see the fleet but no more combat will be possible in that sea region because either your or the other fleet is fleeing. Which is the reason I switched to counter symbols instead of those funny images for fleets and army units. With counters I can see much better in which direction the enemy is fleeing which allows me to order my fleets to follow and hunt him down.