Making a solar-electric bike from a kit is one thing, but this solar-powered boat is a master class in hacking at all levels, from the solar drive train to the pontoons, and even the anchor.

The 7.6-meter boat is designed for up to 13 passengers. The catamaran design has a canopy space for integrated PV. It can operate purely on solar power at a reduced speed of about 7.4 km per hour.

Test results of the different boat propeller designs. (Credit: rctestflight) Interestingly, the 2-blade FDM-printed propeller ended up performing the best, while the bi-blade design (with two sets ...