[RidgeRunner]

Carry at least the minimum USCG requirements for daytime and nighttime signals. Get familiar with how and when to use them. Same goes with a VHF and the fire extinguisher. Carry a cell and/or a Epirb/SPOT/Personal Locating Device. Consider carrying a handheld VHF and a ditch bag. PFD's save lives but only if you wear them. Buy and attach those personal strobe lights to all PFD's for after dark boating. Learn how to navigate by dead reckoning using a chart, compass and a timepiece. Make a cheat sheet with your approx. lat/lon of your favorite places, laminate it to make it waterproof and carry it with your flares and VHF so you can rattle them off even if all your other systems fail. Don't rely solely on your fancy pants chartplotter to get you home. (We all mash the enter button as fast as we can after powering up our navigation devices, in doing so you recognize that you should not rely solely on anything that requires DC current in order to work) Know what heading will take you to the house when you run offshore. File a float plan with a friend/dockmaster/marina. Join a tow service. Learn the difference between simple towing and salvage. Carry some liability insurance in case the worst happens. Familarize yourself with your surroundings, especially true in new places.(Ask around, most folks don't mind helping out the handicapped)
#1 -BE PREPARED FOR ANYTHING/EVERYTHING - Water never stops.
#2 -Never take your boat out unless it is 100%. (Mechanically Speaking)
#3 -Don't push your luck against adverse conditions. There will be other trips.
#4 -Never get into the wiggle water as captain. Clear heads make good decisions.
#5 -Be mindful of other boaters, never assume they see you, never presume to know their state of mind, condition of their vessel etc.

I know it started as a trailering thread, but why stop there?