For an almost complete list of the keys, download the getting started thingy beside where you download the game. It is a 60 some page manual for the game. On the last page is a listing of most of the hotkeys used in game. The manual also has alot of information in it that could be useful. I'm not to sure though I have not read it, I spend all my freaking free time trying to sink stuff.

F5 in-battle for a complete listof all controls.

f9 turns the music on/off

F11 will turn the zoom function on and off, use the mouse wheel to zoom in and out after you've turned it on.

also another useful key is shift + f1 and shift +f2 this will turn on those scoreboards that appear whenever a ship is sunk.

Hello, to enable zoom mode press F11.
You can then use mouse wheel to zoom in and out, otherwise use [ and ]

SlowHands