Here is a list of controls for Ocean Conqueror by Rack It.

Q/A - increase/decrease speed
5/8 - turn rudder left/right
4 - switch readjustment of rudder on/off
 (If this option is off, the rudder will automatically centre itself
 after pressing 5 or 8 and the submarine will stop turning. If this
 option is on, the rudder will not centre itself and you will have to
 adjust the rudders using 5 or 8 so that the submarine stops
 turning.)
W/S - decrease/increase depth
 (When you are submerged, the map is shown, and the submarine also
 automatically changes to electric operation. The submarine requires
 air to be raised - if you run out of air, you will not be able to
 raise it and you will be stuck below the surface!)
6/7 - fine-tune depth
9 - fire torpedo
0 - fire missile

M - switch between map and periscope
R - change magnification of radar
O/P - decrease/increase magnification of periscope
1/2 - turn periscope left/right
B - switch between electric and diesel operation
 (You can only do this when the submarine is at the surface. When the
 submarine is submerged, it automatically uses electric operation.)
V - switch air compressor on/off
 (You can only use the air compressor when the submarine is at the
 surface. The submarine must also be using diesel operation and be
 moving.)

SHIFT - switch between real time and accelerated time
N - switch engine noise on/off
H - pause (any key to unpause)