Having been a boy scout when I was in my youth safety was always not only important but a part of everything we did. It's instilled in me and because of this I probably carry more than I should but our motto was, "Always be prepared."
There are a ton of things you can take with you to make any nasty situation a bit more comfortable but luckly for me I have never had to use any of the stuff in this bag. One thing though... Make sure you update your first aid kit when needed because some of the meds expire, as well as the flares.
I'll take you though my bail out bag:
Here is the bad full of safety/survival goodies
First Aid Kit - Meds, anti itch cream, gauge, tweezers, Etc...
Water bottle
Flares
Hand warmers
Fluorescent green sea dye survival marker
Survival Kit
Extra batteries
cord
signal mirror
compass
Waterproof matches
Space blanket
Small roll of duct tape
PFD:
USCG whistle (cool thing about this is it works even when wet)
Knife - Mine is a Gerber River Knife (make sure it wont corrode)
Water proof camera
Throw Rope - This I attach somewhere on the boat mainly on the bail out bag.
All together it seems like a lot but it fits into a small 10L bag and it didn't cost me a fortune especially since I gathered all of it over time.
I often think I carry more that most recreational boats do but since I'm more liable to get into trouble I suppose it's ok to over do it.
Please comment if I'm missing something I'll be sure to add it!