Well how about optimising the game engine or something? Look at this site:
http://www.navalwarfare.org/
And this game:
http://forums.navalwarfare.org/forumdisplay.php?f=9
It's a campaign simulator for the old game Fighting Steel called Thunder at Sea...and simulates fleet movements with a fair amount (but simple 2-d map graphic) of factors added in, weather, air or sub attacks, ... and it calls up the game when ships sight each other for surface combat. It also has very high compression...don't know if it would help.