I think @tmassey had a story about receiving messages from’ the coast guard after a dive because the pressure at depth had pressed the buttons on his PLB (before getting a canister) and the helicopter was just about to take off …Vacuum way, I imagine it could press any uncovered buttons, so be aware of that. A cover made custom and secured on a vacuum bag maybe. One thing I think I heard someone say on this forum, is the vacuum plastic bag is cut open at the surface and maybe discarded or nicely in a panic mode put in a bc pocket?