It would be a nice add... but smoke is a double edged sword. Think of how some use (or misuse) it in tank battles now.
I can see it now...
PLAYER1: multiple cons inbound on C32!!!
PLAYER2: rgr... in the 5" guns now. I see them... low on the water.
PLAYER3: Im gonna lay smoke wiht mah PT boat!
(30 seconds pass after player 3 has laid large amounts of smoke all around the cv)
PLAYER2: F@#K!!! I cant see S%#T!!!
PLAYER1: Bombs falling!!! Turn the boat!!!
PLAYER2: Too late!
SYSTEM: Ship destroyed