>> “can’t they just use a wrench and tap the SOS on the hull?” <<
If you were at the bottom of the ocean in a rusty tank, would you be tapping on the sides?
.
If still alive. And no armed political officer in the compartment with me...
In the freezing cold water, little oxygen, no lights, upside down trapped below wreckage and debris? You might freeze to death before dying from lack of oxygen.....
Ed Kennedy’s girlfriend/lover died after only 12 hours submerged.