I spend a lot of time looking at boat pictures on line for inspiration. Here’s one I think is wonderful but I’d want something I could stand up in, at least in the galley area, anyway. Nevertheless, this is beautiful. A small outboard to power it which would be economical to purchase and to run, and look closely and you’ll see the auxiliary power is a set of oars. I don’t think it would be something you’d want to live on full time,but it sure would be a good vacation getaway.
Paul Rainey designed and built his tiny houseboat himself. He’s taken it through Florida and the Erie Canal. I found this at: http://wilkinsonphoto.blogspot.com/2012/06/little-house-on-water.html
One More Good Adventure 
As a potential marine build material here in Chiriqui, I am doing a soak test on a 2x3x half in. piece of Okoume “marine” plywood bought from a Puerto Armuelles ferretaria/agropecuria store. So far so good after almost 2 weeks in a spot that is almost a permanent puddle from roof runoff. It is soaked through and no delam even though I pick at the layers. Boil test comes next. I paid 27/sht. & think Cochez has the same stuff for less but must confirm after the test concludes.
I’ll be interested to hear how it turns out. There is a place here in David I’ve checked out called “Plywood y Ferreteria” They will order MDO and HDO ply. Are you familiar with that? Google it and see. Used for road signs and supposed to have great durability.