Referring to @MaxMaker post, I create a new thread in order not do jam the “No drilled masts” onee
Since we’re in water, and the vessel light (70 to 120 kg all included) I think that compressed air would do the job nicely. 30x20x10cm sized suitcase oil free 180L per minute 1100W cost 40€ from Action, 60€ from LIDL. Then, I think the rotative core from pneumatic wrenches like the LIDL one requires bigger compressors because they have to deliver a 11 to 15 mN torque for each bolt of a car wheel … would be interesting to have an insight into smaller air engines … One big issue with those small oil-free air compressors is their pour duty cycle eg 10 minutes on for 10 minutes off.
Maybe the small 3-4 bar compressors for car tyres could do the job if the duty cycle was OK.
Check out the AE3, it fits the Nm and rpm, the down side is the operating pressure! Maybe with a diving tank instead of a battery? It would give only one minute of running time
