All bets are off if you can't recover from a knockdown. If that means you can only go out into the ocean with a support launch, so be it. It's no fun bobbing around on the wide open ocean....don't ask me how I know.
We beach launch, and go for shorter sails than you do so,as far as equipment needs go, YMMV
Personal equipment (all tethered):
Life vest - always worn.
On the boat:
A small spares kit. - shackles, pins and ring dings. some cord.
tiny roll of duct tape.
I used to carry a compass, but foolish as it may be, no longer. We only sail in VFR, and even if pea soup formed out of no where, the sea state is consistent enough to guide us back to land. Being beach launched, I've got seven miles of island where I could put it in (but I haven't missed my own beach yet.) But, I will not contradict the recommendations here to have one on board.
You will also need a throwable.
Edit: I forgot the Leatherman along with the spares.
Also if you have an engine, you'll need an extinguisher and Visual Distress Signals. (Not a bad idea to have the VDS, regardless.) For the USCG guide, see http://www.uscgboating.org/assets/1/...ations/420.PDF