Writing down movement for a lot of ships is a bit too cumbersome for me and really slows down the game. Why not try identical national counters to represent the ship types and let each player have two or three blank markers to place at the start of the game.
These counters would have the ship type on the underside eg B, AC, Cr, D, S, T. Of course it’s a fair bet that those single units being loading on a couple of counters are on destroyers (or are they a couple of deceitful transports?)
Players would move these markers as they wish, and they would only reveal them in attack phases (optional), or when unloading (compulsory) . A player could forego revealing an important ship (or blank), to add to uncertainty for his opponent.
Any blank counters forced by combat to reveal themselves would be returned to the base sea zone. Players would pay the correct cost for new ships, but when placing in the base sea zone, they would be placed as counters.
What do you think?
Air recon might need to be considered……