How about a low power boat with a micro cabin? I'd most like a boat that would sleep very cozily two, but I might be willing to build one that would only sleep one. I know you like to build boats that can be powered with 3hp or less, so it would have to be fairly long to be narrow enough to work.
Have you considered something with a micro cabin for solitary cruising. Here's a picture of one similar to what I'm thinking.
This one is 20 feet and has a 3+ foot beam. Has a 6 foot 6 inch sleeping area on the "cabin". It's pedal powered and has actually seen use on the Great Loop. Designed by Paul Gartside.
Jbo
