Angus Rowboats have produced a sliding seat rowing shell you can sleep in, designed for expeditions to remote regions.
When you get to a bay, you just attach a pair of stabilisers to the outriggers, get the tea table out of the foredeck, and brew up. The foredeck contains a bunk.
It is a very interesting design but not for me. If I ever get to go long distances it will be in a boat you can sail as well as row, with enough room inside to move around without feeling I will get an impromptu bath if I put a foot wrong.
On the other hand, Colin says in his blog that he had a comfortable night anchored right here, so the boat is clearly capable of stopping in places I wouldn't dare spend the night in.