Cautious navigation while submerged

[Mylander]

Originally Posted by Aimbot

I've dove to 140 feet on a clear day and was able to see pretty well even without light. In clear pacific water you'd have decent vis to 200 feet, I'd guess.

Been there, and deeper. (168' on SCUBA, in the Bahamas, but not by choice) You can see, but how far, and with what color resolution - none. it's all blue and grey and black down there unless you bring your own light - and WW II subs didn't have headlights. And you're talking about the clearest, calmest possible conditions with the most possible ambient light (clear day) - not something I'd want to count on as a sub skipper for U/W navigation. Cloudy day, current stirring up particulate matter, and forget it. Your vis would be very limited. Certainly not enough for Bernard to hang out in a torpedo tube shouting directions :rotfl: Which were then shouted into a voice tube, which were then relayed to the engine room telegraph, which were then, CRUUNNNCHHH!!! "We're taking damage sir!"

I don't claim to have all of the answers - I'm just not buying that scenario. How did they do it? Did they keep a certain minimum depth under keel based on their charts? periodic sonar soundings? I don't know. I'm a sailor, and as such, my depth under keel (5') is always on my mind. But I have GPS charts with spot depths, and a sonar depth sounder which is continually updated, and sounds an alarm if I get too shallow. These guys had none of that. Nor could they see what was around them...

Mylander