I never used a 30-subs killer stack myself (read about them, so I know what I "missed"), but I think I use the "new" subs with quite some success (playing as Germany). Following a "Dönitz light" approach I start the war with 40+ subs and have a parallel build of 6 subs running throughout the war. At the end of the first year of the war the subs usually have sunk more than 400 convoys and most of my enemies escorts. I never had such an impressive start like blue emu, but usually my subs kill some carriers during the war. This forces my enemies to build extra convoys, use resources (ships, oil, supplies) to chase my subs and a lot of his troops are out of supply (because he lacks the needed convoys).
So maybe this is usefull for those that have problems with subs.
Most important: Accept that subs have only one purpose: sink convoys (this includes reducing your enemies trade efficiency!) - nothing more. They must avoid battles at all costs and if they get caught they should retreat as fast as possible (but will probably get sunk before the 4 hour limit is reached). This means you should expect heavy casualties, but don't let that stop you. It sometimes happens, you loose 10+ subs in a single month, nothing you can do about it.
I never put more than 3 subs into a fleet, if I only have 2 subs available fine as well ... this really helps your subs to avoid battles (lower visibility). If I group them in stacks of 6 or more, I find that the enemy spots and engages them too often (no blasphemy intended
). I usually don't deploy the subs in the sea zones surrounding Great Britain, I find that they get caught too often in these waters (maybe because of the RAF ... not sure). Good hunting grounds have allready been mentioned in this thread, I usually place them all over the atlantic with a concentration on the coast of spain, portugal and north-western africa, plus some near the carribean, halifax, south africa, the falklands and murmansk (to reduce british trade efficiency). You can even place them in the mediteranean before war breaks out (but once the war starts, the subs are trapped there). I set their mission to convoy raiding, night only and let them do this for at least 5 months ... I don't know if this is gamey (they never run out of torps, food or diesel), but it definitly helps to reduce micromanagement. I try to avoid assigning two sub fleets to the same sea region, because two fleets are easier to spot than one...
A good advice that has allready been given is to support your subs with as much airpower as possible. Especially the bay of biscay should be well covered by fighters and naval bombers. CVL on port strike kill docked subs at an awesome speed, don't let them get near you naval bases!
I always research all the naval doctrines available (not abandoning the Doctrine path), but I don't know if they are all necessary ... I think the sub related doctrines should definitly be researched.
If you want to further improve your subs performance get Spain into the axis (doesn't matter if friendly or the german way), the spanish airfields allow the Luftwaffe to cover a bigger portion of the atlantic ocean and this will help your subs a lot. The AI doesn't react very good to this new threat though, it just keeps sending hunter-killer groups in the nearby sea-zones. If you can spare 10 CAS 2, you can easily take out most of the allied ASW capability within half a year through naval strike missions in that sea zones.
So maybe this is usefull for those that have problems with subs.
Most important: Accept that subs have only one purpose: sink convoys (this includes reducing your enemies trade efficiency!) - nothing more. They must avoid battles at all costs and if they get caught they should retreat as fast as possible (but will probably get sunk before the 4 hour limit is reached). This means you should expect heavy casualties, but don't let that stop you. It sometimes happens, you loose 10+ subs in a single month, nothing you can do about it.
I never put more than 3 subs into a fleet, if I only have 2 subs available fine as well ... this really helps your subs to avoid battles (lower visibility). If I group them in stacks of 6 or more, I find that the enemy spots and engages them too often (no blasphemy intended
). I usually don't deploy the subs in the sea zones surrounding Great Britain, I find that they get caught too often in these waters (maybe because of the RAF ... not sure). Good hunting grounds have allready been mentioned in this thread, I usually place them all over the atlantic with a concentration on the coast of spain, portugal and north-western africa, plus some near the carribean, halifax, south africa, the falklands and murmansk (to reduce british trade efficiency). You can even place them in the mediteranean before war breaks out (but once the war starts, the subs are trapped there). I set their mission to convoy raiding, night only and let them do this for at least 5 months ... I don't know if this is gamey (they never run out of torps, food or diesel), but it definitly helps to reduce micromanagement. I try to avoid assigning two sub fleets to the same sea region, because two fleets are easier to spot than one...A good advice that has allready been given is to support your subs with as much airpower as possible. Especially the bay of biscay should be well covered by fighters and naval bombers. CVL on port strike kill docked subs at an awesome speed, don't let them get near you naval bases!
I always research all the naval doctrines available (not abandoning the Doctrine path), but I don't know if they are all necessary ... I think the sub related doctrines should definitly be researched.
If you want to further improve your subs performance get Spain into the axis (doesn't matter if friendly or the german way), the spanish airfields allow the Luftwaffe to cover a bigger portion of the atlantic ocean and this will help your subs a lot. The AI doesn't react very good to this new threat though, it just keeps sending hunter-killer groups in the nearby sea-zones. If you can spare 10 CAS 2, you can easily take out most of the allied ASW capability within half a year through naval strike missions in that sea zones.
