Where next? please give your idea's and feedback

Thank you for the compliment. Well the most obvious route from here is new OOB's (Atlantic and Mediterranean come to mind) and a campaign system. The latter might prove more difficult since I have few experience playing campaigns, let alone designing them.

What about adding small craft, MTBs etc? Treat them like planes?

A couple of years ago I happened across a couple of books at my local library which had a wealth of information about fleet composition and engagements, possible and actual. I can email you scans of what I typed up from them?

Hello Andrew,
The German OOB and the data cards contain the German Schnellboote, which is somewhat comparable to the MTB. There are also special rules for their operation in the rulebook. I can make cards for them if people are really interested in them. If I remember correctly they are somewhat one-off weapons.

Information on OOB's is always welcome, but I do have a lot of sources for them already. Still, any extra information can always come in handy.