OK, I found several 10' Porta-botes for sale on Craigslist for
reasonable prices. Then I considered how to store them on my 28'
boat. Uh oh. 10' is longer than the cabin top and will cover all the
windows on one side. I could put it against the lifelines but then it
covers where the jib sheets go.
Maybe the Porta-bote is not the answer.
OTOH, I can get a cheap inflatable from West for about $400 and put a
cheapo e-bay 2 hp outboard on it.
Maybe there simply is not an answer but I do not believe that.