Electric Propulsion
There are times when doing away with petroleum-based propulsion systems actually make good sense. If you rely on dinghy transportation for daily life, as most coastal cruising sailors do, it’s hard to top the practicality of the “TEMO" concept:
No doubt, there are patents that govern the commercial development and sales of this technology, but it looks to me like ‘home-brewing’ this contraption would not be all that difficult—owing to computer generated fabrication, and the increasing availability of a variety of designs in batteries….. So it is with “tinkering around with boats."
/fl