[bestclimb]

Originally Posted by Jyden

With the underwater drive / propellar permantly out, you should install it so that you have two options. "free wheeling" or "Power generating mode".

The propellar will spin as you sail. If theres a free gear it will spinn without much resistance, but if the electric PM motor is fitted you could use that as a generator to charge your batt3ries.

Resistance while generating power would be higher, but I will proabably only reduce boatspeed with something like 1 knot.

And you would be making your own current for the batteries and the boat.

Thoughts on that ?

Likely less than a knot. The limiting factor for boat speed is hull length at the water line. A little extra drag in the water will not substantial slow the boat, as once the hull comes up to it's theoretical limit the drag from trying to drive up onto the bow wake goes up exponentially.

For cruising boats there are commercial tow behind and drop down generators to keep the batteries topped, would be neat to see one piece of equipment pull double duty.

I looked at a lot of systems when I had my boat for dc generation without running an inboard diesel, that I mostly wanted to pull out and replace with a small electric motor for docking when conditions made docking under sail "challenging". I had well built a 32 foot ferro-cement full keel double ender. it was cutter rigged.