Radar depth was 45 feet and that would work for me ... I'm the captain now (when Sh4 gets here) and I will surface under them if I have to ... scope's were only used for final bearing and shoot anyway ... 5 to 7 seconds.
Plus most boats charged batteries at night and if they detected a convoy on radar, the plotting team would inform the captain how far in front they had to be to have a firing solution ... they would then race ahead on the surface to get into position.
Periscopes are for candy asses ...
