In bad weather and sometimes just to simply be safe sailors use
jacklines. These lines run from the bow down either side of the mast
to a cleat on the stern and he clips himself into this line whenever
he leaves the cockpit. Maybe powerboats need jacklines in case the
boat turns over. The boater would not clip himself to said lines but
would stand on them when he overturns to mostly get himself up onto
the hull. Ought to be easy to rig when weather gets bad. What y'all
think of this?
Another easy piece of survival gear might be a big trash bag in your
pocket. Once you turn over and are wet, being in the water makes you
lose heat far colder than being in the cold air simply due to thermal
conduction in the water vs air. You feel colder in the air but you
lose heat faster in the water. So, once you hoist yourself onto your
"Jacklines", pull out your trashbag, poke arms and head holes and you
have something to trap body heat and protect yourself from wind. Yes,
this really does work, it once saved my life when trapped in a cave at
the bottom of a waterfall for 6 hours.