Slitherine

Now that GS has the concept of subs evading attack it seems that surface ships (DD/BB/CV) ought to be able to evade sub attacks as well. Subs were slow compared to such surface ships, and could not attack them so easily. I don't think subs attacked surface ships very often. Maybe if a sub does not start a turn adjacent to a surface ship then there should be a significant chance of the surface ship evading the attack. Also, currently subs can attack surface ships in port turn after turn. This is very unrealistic. Probably ships in port should be able to evade most of the time.

We added surface ship survivability vs subs as an alternative to evasion. Those values can be changed in general.txt.

SUB_NAVAL_ATTACK_BONUS_VS_CONVOY 1 /* Value added to submarine naval attack if defender is a convoy */
BB_SURVIVABILITY_BONUS_VS_SUB 1 /* This number is added to the battleship survivability when defending against submarines */
CV_SURVIVABILITY_BONUS_VS_SUB 1 /* This number is added to the carrier survivability when defending against submarines */
DD_SURVIVABILITY_BONUS_VS_SUB 2 /* This number is added to the destroyer survivability when fighting submarines */

Evasion is that you can dive and avoid being hit. Surface ships can't evade from subs lurking. Even transports and convoys were faster than the subs and they got hit regularly because the subs ambushed them. The same with surface ships.

What we need instead is that subs become so damaged going after surface ships so they don't try to do it regularly. Going after depleted surface ships to finish it off is one thing. Ambushing escorts instead of convoys means something is wrong.

Submarines were definitely capable of hitting surface ships in port. The most famous sinking was the sinking of Royal Oak in Scapa Flow port, Britain's greatest naval base.

http://www.scapaflowwrecks.com/wrecks/r ... inking.php

Even the Tirpitz was attacked by British subs when hiding in a Norwegian port.

In GS you can only make 1 port attack per turn and by doing that you expose your sub to counter attacks. After some Allied surface ships and ASW technology the subs will suffer heavily if trying to attack ships in port.

The main reason subs rarely attacked ships in port was that they exposed themselves too much by doing it. One thing is to do the actual attack, but you need to escape too in shallow waters and a possibility for the enemy to box you in.

With the sub vs convoy damage you will most often be better off attacking convoys than going after the surface ships instead. If you attack surface ships you're bound to take casualties in the attack and have a risk of counter attack the next turn. If you go after the convoy you inflict 10-25 damage on the convoy. Counter attacks will be next turn. To have a similar effect on the surface ship you need to inflict 3-4 hits. Most often you inflict 1-2 hits. To make it even worse you suffer your own losses by going after a surface ship.

The subs are now so lethal so the Allied player needs to invest heavily in naval techs and new naval units. I buy 2 CV's each for USA and UK. In addition I get some BB's for USA and quite a bit of DD's for both countries. I always escort my convoys with 3+ escorts unless I need to transport a blob of units across the Atlantic. The extra PP's spent on building more DD's is won back by convoys reaching home with more PP's.

The easiest way to lose the game as the Allies is to not put enough effort on escorts.

Appreciate the detailed explanation of sub warfare. Thanks!

No question that occasionally subs were able to attack ships in port, but it was not a frequent occurrence due to measures like anti-submarine nets. I am only suggesting that subs should not be able to attack ships in port turn after turn, as frequently occurs in GS (in my experience especially against Italian BBs in port).

As far as evading outside of ports, yes I do understand that surface ships cannot dive and evade the way that subs do. However, surface ships can "evade" subs by being much faster (when subs are submerged). In GS if a surface ship is spotted a thousand miles away multiple subs units (up to 6) can travel the thousand miles and attach the faster surface ship 100% of the time. I think we agree that in reality for subs to attack a surface ship that is moving the sub would have to lie in wait and hope the ship stumbles into it's trap. This is nicely simulated in GS. Why not limit the unreality of the subs moving long distances and attacking faster ships. I think it would improve the game.

FWIIW, I have just detected a minor oversight whilst playing a v3.1 PBEM game.
Viz.
Persian hex 142.52 has a supply level of 0.

Perhaps one to tweak in v3.2.

Kind regards.

I checked hex 142,52 and it has normal supply level (3 when neutral and 4 once Persia is activated). Try to start a new game like the 1942 scenario and check for yourself.

I've noticed hexes registering as 0 supply, but only when they are cut off from a supply path for your side.

Thanks for that information ~ my oversight.

Never too old to learn.