It would be more useful if the answer derived in your excell sheet was related to "bearing to target"... you know: "fire when target reaches bearing blah blah" instead of the "Fire when target is this far from the rendesvouz point" deal that you currently have. The reason? you can have your sonarman continously shout bearing to target data, but not distance
Anyway, you don't need to do this by hand or in anyway outside of SHIII... you have a targeting computer in your U-boat, use it
