>>4402
The best naval strategy in HOI games is generally to keep your feet dry as much as possible. Navies really aren't that important anyway, as Pdox has a bad habit of treating naval combat as an afterthought and consequently the AI usually doesn't know how use its fleets right.
Your naval strategy and composition will depend a lot on your country and situation. I recommend you look at the manual, naval info starts on page 127. Make sure you actually read it, and read the whole section; don't just skim and read the parts that look important. I made that mistake at first and wound up missing a lot of important stuff.
http://cdn.akamai.steamstatic.com/steam/apps/73170/manuals/Darkest_Hour_MANUAL_V1.0.pdf?t=1411052400
As the units' roles not covered well in the manual, here's a rundown on each ship type:
>Subs are best for convoy raiding
>Heavy subs are better in conjunction with surface ships than normal subs, but still fine for convoys
>Destroyers are best used as sub killers
>Light cruisers are a bit better at surface combat than destroyers but a bit worse against subs; I generally put at least a few in my convoy defence fleets, I even favor them over destroyers in more contested areas if I can afford to
>Heavy cruisers are decent at everything, but excel at nothing. They are the smallest capital ships
>Battlecruisers are good for surface combat, not so good at everything else. I don't use them much because all their potential roles can be better fulfilled by more specialized ships; they're essentially just the poor man's battleships
>Battleships are better for surface combat than battlecruisers, but a bit worse at everything else
>Aircraft carriers are your most important ships by far, fleets that contain them should be focused on defending them so your CAGs can do the dirty work
>Escort carriers are pretty useless once you get aircraft carriers. I just avoid building them altogether
And some additional pointers:
>Build the CAG before you build its carrier; carriers are utterly useless without CAGs but CAGs can operate independently of carriers, IIRC
>Good air attack and defence stats only go so far and are no substitute for adequate carrier support
>Conduct port strikes often. This will make it harder for your enemy to maneuver and supply his fleets, and if ships are in the port you're bombing, you kill two birds with one stone
>Use naval bombers with interceptor escorts to guard your shores; all but the biggest and best fleets will have no answer to this
>You're only required to have one screen per capital ship in your fleets, but I try to have as many as possible, as capital ships are major investments (maybe not so much for heavy cruisers, but still) worthy of all the protection you can give them
>A fleet in poor supply is utterly fucked if it gets into combat
Hope this helps. Good luck