The Annapolis Sailboat Show takes place this week on City Dock, and I’ll make an assumption about most of the people who plan to attend: They will not expect to see a boat that comes in a couple of bags. They will expect something conventional — boats that weigh 8,000 pounds or more, that come on trailers and sit in marinas. Most show-goers will not expect to see a sailboat that inflates and assembles in less than an hour — actually, less than half an hour, once you get the hang of it and don’t waste time gabbing with a newspaper columnist.