Radar vs. Snorkels

[commonJoe886]

Radar adds both longevity and lethality, allowing a submarine active abilities to spot and evade hostile patrols as-well-as locate enemy convoys. Snorkels only provide a passive ability to hide. Additionally, radar can be upgraded 5? times, snorkels 2.

Seems like a no brainer. Always put radar systems on your subs.

 

[DGuller]

Radars don't allow you to fire off torpedoes at destroyers with impunity. You shouldn't be evading patrols, you should be sinking them.

 

[eastcoastceojam]

In a post from a few months back, one of our forum experts agreed that radar is better than snorkel.

Sub Radar buffs the Sub's detection of enemy ships, and lets them avoid being disrupted by engagements with anti-sub patrols. With 1940 Subs and Trade Interdiction doctrine, sub visibility is already minimized, so the snorkel has limited impact compared to detection-boosting radar.


Full post linked below:

With good RADAR on subs, they can not only find convoys easier, but avoid enemy patrols easier by detecting the patrols and moving away from them. That's also why capital ship raiders need floatplanes and RADAR.

I haven't tested it in awhile, but the last time I did, RADAR helped subs avoid ASW patrols better than the snorkel. The snorkel helped submarines avoid detection during actual battles, but with 1940 subs and the raiding designer, the subs really only reveal themselves when firing torpedoes anyway.

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When I last played through 1941, MtG was released with patches. I found the uboat war was very effective, but only after france fell and lvl 1940 uboats were developed and fielded. Before France fell, I found uboats were wiped out by combined...

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[DGuller]

I don't want to scare off ASW patrols, I'm happy to greet them with torpedoes. All I need is to make sure that I don't reveal myself while sinking them. I suspect that the conclusions reached about radar vs. snorkel rely on the assumption that you should be avoiding everything other than convoys with the subs, which is a bad assumption with the current mess of the naval game.

 

[MR2]

What about a mix of multiple small fleets of snorkel or radar equipped subs?

 

[Secret Master]

I don't want to scare off ASW patrols, I'm happy to greet them with torpedoes. All I need is to make sure that I don't reveal myself while sinking them. I suspect that the conclusions reached about radar vs. snorkel rely on the assumption that you should be avoiding everything other than convoys with the subs, which is a bad assumption with the current mess of the naval game.

Then take my advice in those posts and add to it the patrol order. With Radar you will find and sink warships faster.

 

[DGuller]

Then take my advice in those posts and add to it the patrol order. With Radar you will find and sink warships faster.

I don't think patrol order on submarines is that effective, at least not in the initial stages. I can cover a lot more water with convoy raiding orders than I can with patrol orders, and warships find me anyway, I don't have to look for them. I win if I sink all the convoys, and I win if I sink all the warships trying to protect the convoys.

Once I sink every convoy, it is true that I need to use patrol orders if I want to keep engaging, but at that point I won anyway. What's the point of designing subs in order to finish off defeated enemies slightly faster? I'd rather focus on things that will turn the tide of the war when it isn't decided yet, and what will do that is maximizing your attack/detection ratio.

 

[MinhowMinhow]

Well, I do prefer snorkels, because it makes very hard to make a submarine be spotted and make him launch lots of torpedoes. The trick is is to make subs be on max agression setting, because they don't run away and stack torpedo reveal and visibility decreasing bonuses.

Edit: Yes, this picture is from another topic, but shows how snorkels are great, at least for SP.

 

[Secret Master]

I win if I sink all the convoys

Then you want RADAR to detect convoys, too.

Of course, if you think RADAR isn't helping that much, I might argue that maybe the snorkel won't, either, using your current parameters. At that point, you can save yourself the production cost and just not put either one on the subs.

 

[DGuller]

Then you want RADAR to detect convoys, too.

Of course, if you think RADAR isn't helping that much, I might argue that maybe the snorkel won't, either, using your current parameters. At that point, you can save yourself the production cost and just not put either one on the subs.

I just don't see what problem I'm solving with the radars. I don't have any problem detecting convoys. I don't have any problem drawing in the fleets that are defending the convoys.

The only thing that can be a touch and go is whether my detection is low enough to keep my sub losses low due to detection by either warships or planes. My subs definitely do get detected sometimes by the warships I'm trying to sink, it's just a matter of maximizing the number of torpedoes I fire for each case of detection. That seems like a clear case for the snorkel.

 

[Secret Master]

I don't have any problem detecting convoys.

When there are still convoys to hit, and I have enough submarines operating in the Atlantic, some convoys still slip through the net when I don't have RADAR.

That being said, I'm often facing off against humans that are better at optimizing routes than the AI, so it might matter more in those situations than against the AI.

That seems like a clear case for the snorkel.

Except snorkel doesn't matter when torpedo fire reveals submarines.

That's one reason I think Torpedo Reveal Chance matters more than actual submarine visibility against the AI once you get to 1940 submarine hulls. Yes, you want low visibility, but if your subs reveal themselves when firing torpedoes, reducing visibility further doesn't help with that.

 

[pheonicia]

When there are still convoys to hit, and I have enough submarines operating in the Atlantic, some convoys still slip through the net when I don't have RADAR.

That being said, I'm often facing off against humans that are better at optimizing routes than the AI, so it might matter more in those situations than against the AI.



Except snorkel doesn't matter when torpedo fire reveals submarines.

That's one reason I think Torpedo Reveal Chance matters more than actual submarine visibility against the AI once you get to 1940 submarine hulls. Yes, you want low visibility, but if your subs reveal themselves when firing torpedoes, reducing visibility further doesn't help with that.

I found in my last game I was losing way more subs to planes than enemy ships, this was with snorkels and loading drill master on the admiral. Would lowering torpedo reveal chance have helped me in that situation?

 

[DGuller]

Except snorkel doesn't matter when torpedo fire reveals submarines.

That's one reason I think Torpedo Reveal Chance matters more than actual submarine visibility against the AI once you get to 1940 submarine hulls. Yes, you want low visibility, but if your subs reveal themselves when firing torpedoes, reducing visibility further doesn't help with that.

I don't think that's the case, if Wiki is correct: https://hoi4.paradoxwikis.com/Naval_battle. Torpedo reveal chance is affected by both torpedo reveal factors and sub visibility factors.

 

[Secret Master]

I found in my last game I was losing way more subs to planes than enemy ships, this was with snorkels and loading drill master on the admiral. Would lowering torpedo reveal chance have helped me in that situation?

No. I don't think NAVs ever care about that, especially if they are bombing you outside of combat.

I don't think that's the case, if Wiki is correct: https://hoi4.paradoxwikis.com/Naval_battle. Torpedo reveal chance is affected by both torpedo reveal factors and sub visibility factors.

I will rephrase my statement, since it was missing some qualifying language. Torpedo Reveal Chance reduction has far more impact on submarines becoming visible than snorkel does when computing the chance of submarines revealing themselves by firing. Looking at the formula from the wiki, sub visibility in that formula is a value divided by 100, so a 10% reduction on existing visibility (snorkel tier 1) would move the needle around 4-5 points before being multiplied by the 3.5% chance. But the Torpedo Reveal Chance subtracts from 100% in another part of the formula before being multiplied by the 3.5% base chance. Unless I'm particularly bad at math today (and that's entirely possible), Silent Hunter would have a bigger impact on whether or not torpedo fire is revealing subs than a snorkel and it does not require technology or production cost on the submarines. Stacking the Electric Torpedo and Naval Doctrines would further increase that effect.

Electric Torpedo requires research, but costs nothing in terms of production. Ditto for naval doctrines. But if you are running submarines, you're probably grabbing torpedoes and trade interdiction anyway.

 

[DGuller]

I will rephrase my statement, since it was missing some qualifying language. Torpedo Reveal Chance reduction has far more impact on submarines becoming visible than snorkel does when computing the chance of submarines revealing themselves by firing. Looking at the formula from the wiki, sub visibility in that formula is a value divided by 100, so a 10% reduction on existing visibility (snorkel tier 1) would move the needle around 4-5 points before being multiplied by the 3.5% chance. But the Torpedo Reveal Chance subtracts from 100% in another part of the formula before being multiplied by the 3.5% base chance. Unless I'm particularly bad at math today (and that's entirely possible), Silent Hunter would have a bigger impact on whether or not torpedo fire is revealing subs than a snorkel and it does not require technology or production cost on the submarines. Stacking the Electric Torpedo and Naval Doctrines would further increase that effect.

Electric Torpedo requires research, but costs nothing in terms of production. Ditto for naval doctrines. But if you are running submarines, you're probably grabbing torpedoes and trade interdiction anyway.

A couple of points:

1) A multiplicative factor is a multiplicative factor. Whether it's multiplied by 3.5% or 100000% in the end doesn't matter. In the torpedo reveal formula, sub visibility is a direct multiplicative factor, so a 10% reduction in sub visibility directly translates into a 10% reduction in torpedo reveal chance.
2) The torpedo reveal factor more or less functions as a multiplicative factor as well. The (100% + naval_torpedo_reveal_chance_factor) more or less functions as a multiplicative effect. Unless the base naval_torpedo_reveal_chance_factor starts out at something far away from zero before modifications, we can conclude that a 10% reduction in torpedo reveal chance has more or less the same impact as a 10% reduction in sub visibility.

 

[Secret Master]

10% reduction in sub visibility.

Except that sub visibility would be modified by 10% before being divided by 100 according to the formula.

So, assuming Torpedo Reveal Chance Factor is, say, 15 because Silent Hunter is -15% torpedo reveal chance, then I'd expect the value in first parentheses to be 85% (or a value of 0.85). But sub visibility (14.2 visibility at 1940 tech with no designer or other modifiers) would be reduced 10% by a Tier 1 snorkel, making it 12.78 visibility. So, without a snorkel, the third parentheses would be .142, and with a snorkel it would be .1278.

As I missing something here? Wouldn't Silent Hunter matter more? And doesn't torpedo reveal chance overall have more impact on the formula than submarine visibility? (Positioning is another kettle of fish entirely.)

 

[DGuller]

Except that sub visibility would be modified by 10% before being divided by 100 according to the formula.

View attachment 651717

So, assuming Torpedo Reveal Chance Factor is, say, 15 because Silent Hunter is -15% torpedo reveal chance, then I'd expect the value in first parentheses to be 85% (or a value of 0.85). But sub visibility (14.2 visibility at 1940 tech with no designer or other modifiers) would be reduced 10% by a Tier 1 snorkel, making it 12.78 visibility. So, without a snorkel, the third parentheses would be .142, and with a snorkel it would be .1278.

As I missing something here? Wouldn't Silent Hunter matter more? And doesn't torpedo reveal chance overall have more impact on the formula than submarine visibility? (Positioning is another kettle of fish entirely.)

I think what you're missing here is that everything is relative. Dividing by 100 affects nothing at all, all the multiplicative factors cancel out.

In the case of silent hunter, you're modifying your torpedo reveal chance by 0.85/1.00 = 0.85. In other words, a 0.85 modification factor is a 15% reduction.
In the case of the snorkel, you're modifying your torpedo reveal chance by 0.1278/0.142 = 0.90. In other words, a 0.90 modification factor is a 10% reduction.

In the second case, if in that formula 100 were instead, say, 17845.239, you would be modifying your torpedo reveal chance by 0.00079573/0.00071616 = 0.90, which is still exactly a 10% reduction.

Yes, silent hunter has more impact than a snorkel, but only because silent hunter is a 15% bonus while snorkel is 10%. As far as the actual impact of the magnitude of these bonuses, either one has the same impact here.

 

[bitmode]

As I missing something here? Wouldn't Silent Hunter matter more? And doesn't torpedo reveal chance overall have more impact on the formula than submarine visibility? (Positioning is another kettle of fish entirely.)

I depends. 15% is obviously better than 10%, but @DGuller is correct that both are factors in the same product. The "/100" could just as well appear elsewhere in the product. As presented, it is simply the order in which the code calculates the formula.

Being a ship attribute (which I hoped would eventually be documented elsewhere), visibility is condensed more than the other parts of the formula for brevity. It could be expanded to "[...] * (100% + sub_visibility from engine ) * (100% + sub_visibility from snorkel) * hull visibility" so mathematically there is not much of a difference between the two modifiers.

 

[Secret Master]

I depends. 15% is obviously better than 10%, but @DGuller is correct that both are factors in the same product. The "/100" could just as well appear elsewhere in the product. As presented, it is simply the order in which the code calculates the formula.

Being a ship attribute (which I hoped would eventually be documented elsewhere), visibility is condensed more than the other parts of the formula for brevity. It could be expanded to "[...] * (100% + sub_visibility from engine) * (100% + sub_visibility from snorkel) * hull visibility" so mathematically there is not much of a difference between the two modifiers.

Fair enough. Then it seems snorkel would have a visible impact on subs revealing themselves while firing torpedoes.

I wonder why I never seem to have noticed that in actual shooting situations, though? Maybe it's easy to stack several torpedo reveal chance modifiers that exceed snorkel's impact?

 

[Znail]

I just don't see what problem I'm solving with the radars. I don't have any problem detecting convoys. I don't have any problem drawing in the fleets that are defending the convoys.

The only thing that can be a touch and go is whether my detection is low enough to keep my sub losses low due to detection by either warships or planes. My subs definitely do get detected sometimes by the warships I'm trying to sink, it's just a matter of maximizing the number of torpedoes I fire for each case of detection. That seems like a clear case for the snorkel.

Radar also reduces the time it takes to find convoys wich leads to more sinked convoys.