We've already got SDVs, rubber rafts, and speedboats in ArmA3, but I think the game could do with some extension to naval combat in the form of some new bigger ships. My thoughts were:
- More static objects for sea - cruise ships, cargo vessels, etc. all of which are walkable, as well as the large submarine from some screenshots as a static object.
- Several new, moderately larger ships for each faction - I think a hydrofoil would suit the CSAT style, a vehicle not unlike the Mark V SOC, although perhaps larger and better armed could go for NATO, and AAF might use something with a similar design to a PT boat. I also found several images of an unknown ship which could suit them below.
- Better modelling of damage on naval craft - more parts on a ship. Left/right/forward/back hull, etc.