The 'brief safe' is a disguised safe that no one would ever touch because they look like poop-stained underwear. Or, you could just put your money in the bank, but that's such a silly idea no one would ever do that.
You only become a true man when you rip one of your own arms off and replace it with a robot.
Distress Beacon Watch: Full disclosure, homing beacon signals are going to have a tough go reaching the surface, but signals can get through. Strap on that watch.