Nothing is “Waterproof” just ask anybody that has ever served aboard a Submarine. That’s why Subs have a Test Depth, they have only been tested to that depth, below that they have a “crush depth”.
You ever watch the scene in Down Periscope where the guy in the engine room runs a string sideways across the sub. As the Sub dives the string begins to sag, the deeper they go, the greater the sag. Eventually the water pressure will crush it, like a tin can.
Hmmm...so subs compress the air as depth compresses diver’s lungs?
Does that mean that submariners have to wait at certain depths for their nitrogen to depressurize, so they don’t get the bends, as divers do?
Thanks!
Ed