Blank areas are too far away from your ships to be seen.
Areas with a small wave can be seen, and are empty, but there might be hidden subs.
On top of the screen you see the unit counts (yours : palms) sorted by crusers, destroyers and subs, and the time in tics.
HOW TO PLAY
The action takes place in 2 second tics.
The ships fire automatically.
You can control ships by dragging them to their destinations (tap on a white ship, wait for the enclosing rectangle to appear, move the rectangle to the destination).
Cruisers can move and fire every tic, destroyers every 2nd and subs every 3rd tic.
Cruisers cannot fire on subs.
Subs can be seen only from fields immediately next to them, and not by cruisers.
Cruisers can fire and see for 3 fields in each direction.
Destroyers can fire and see for 2 fields in each direction (subs can be fired only when you are next to them, because of the water bombs).
Subs can fire on fields next to them but can see 2 fields in each direction.
HIts the ships receive are drawn as black dots. A cruiser can stand 3 hits, destroyers 2 and subs 1.
Hits decrease the fire range stepwise down to zero.
Destroy all enemy cruisers to win.
LEGAL STUFF
This game is freeware.
Use it on your own risk.
I tested it on a Palm Vx with Palm OS 3.5 only.
You can have source code if you like.
I wrote it in C with the OnboardC compiler V1.004 beta and RsrcEdit.