I say do it do it do it.
Here is what my friend and I did to our 1974? maybe 84 i forget hobie 16 to do longer trips safely.
OK, so you're already at the ideal weight (about 285lbs) with wetsuits, fleece, PFD, all the basic stuff you'd take out for a day long sailing trip to begin with. So the most important thing is to pack light. This term means so many different things to different people so to understand what light is you need to understand lightweight backpacking gear. A typical lightweight base weight for 3 seasons is about 10-12lbs. The giant frame packs people see in the store weigh about 5lbs by themselves just for comparison. My pack weighs about 18oz. Anyway, read more about light weight backpacking at bpl or some other website.
Next, the hobie. We installed some drains on the hulls which work well enough to drain them even going upwind. They work by venturi principle, the drains we installed are from a finn. They are just a precaution we installed, have not really used them out of necessity yet. We also fabricated some anti pitchpole foils that work pretty well.
Even though weight is an issue, your boat needs backup parts too. Take the minimum in tools and gear you need. We take extra bridal wire, extra shroud, extra set of hardware, extra rudder pins, and a small kit with epoxy and fiberglass mat in it, as well as some putty stuff that mixes up and "fixes" things magically. Keep in mind, this whole kit only weighs about 8lbs or so i guess if that i dunno really.
Take GPS, we also have a SPOT. The spot is sweet because you can call folks to your rescue and the GPS unit transmits your location to the authorities so they can find you. Mine works even in canyons and what not pretty well, just need a straight shot of the sky.
I dunno what else, luck I guess! Its a shame we can't prepare better on the hobie 16 due to weight restrictions but we regularly take trips to the manitou islands/sleepy bear duns or pictured rocks and just run around on a hobie. When there is no wind we drop the mast, lash it down, and the boat becomes very stable. we then just paddle the hobie along like a canoe sitting on the front pontoons. if i had a hobie 18 i'd so put big 8' oars on it, that would be awesome.
Lol just noticed how old this thread is. Its a shame more folks don't adventure on the hobie. Worst case scenario you paddle a boat home lol, so worth it.