Somewhere around 2005/2006 I was delivering a 570 Carver from Georgian Bay to Toronto. On the Trent Severn system one night I docked next to a fella in a 20' wooden, open boat ... looked kinda like a runabout but very unusual. I struck up a conversation with the fella and got a tour (20 seconds). The boat was homebuilt and powered with a Mazda car engine that he had kitted out with a jet drive. His reason for such a curious power train .... it was all he could afford and it had been assembled from whatever bits he could get his hands on.
He launched the boat in Wind River, Wyoming and apparently had to push her through several miles of shallows. He ran her through the rivers, through the Great Lakes, down the St.Lawrence, around Nova Scotia and down the east coast to the Bahamas. His hope is to reach lower South America.
I just recently heard from him and that prompted this post. His name is Spike Hampson, a fascinating guy and his website is a fascinating read.