Thank you very much, Mikko! and hello

I was hoping someone like yourself would come along with an answer... I've always suspected that the U-boat commanders had a "range finder" of some type to complete the firing solution in a timely manner.

Relying on the formula Masthead Height / tan ( stadia marks) would be extremely problematic during real-time considering the state-of-the-art of the equipment of the times. The other factor, of course, was their high rate of success at sinking ships.

Thanks again,

Don