My safety precautions: (mostly for wetsuiting)
*sharp dive knife (blunt tip)
*headlamp, 2 neck lights (one red, one white)
*just added a whistle to the neck light lanyard
* I sometimes (should more often) carry a floating princeton tec strobe light... compact, waterproof, visible for 1 mile... just in case I get swept way out.
*I carry a laminated card with my name, info, and emergency contacts inside my plug bag... If I lose my bag someone can return it, if I am found dead, My family can have their world crushed sooner than later.
* I try to let someone know which spots I will be hitting that night. ( I never say what time I'll be back... I always fish longer than I say i will)
* No deep swimming when alone...
*Started keeping bolt cutters in the truck for cutting out hooks.