Sounds like you might be looking for TMO mod, Tiger Maru Overhauled.
You can find it here.
http://www.subsim.com/radioroom/showthread.php?t=132330
TMO improves the graphics a great deal as well as most all the game play options. It's harder to play than stock but well worth it.
You install it with Jones Soft Mod Enabler JSGME found here
http://www.subsim.com/radioroom/showthread.php?t=156898
Check here for a more complete list of mods.
http://www.subsim.com/radioroom/showthread.php?t=155786
Magic
Edit Sailor Steve types faster than I do.