There a lot of variables shared here. Thank you all for sharing.
I have owned my Cal
Cruising 46 since 1982, still have her and love her.
First, she is a sail boat with an adequate sized engine
4.236 90 HP,
3-1 reduction, so she cruises at 6.2 knots, (calm seas, clean bottom), 1,550 RPM's, 1.1 GPH. I built a mount to hold a 8KW generator
, driven by twin vee belts from the front on the engine, which is aft in my boat which a 3-1 redux Vee drive, 22X 22 Luke wheel
I built a 20GPH watermaker
, 117 VAC, since we intended to cruise
where drinking water
can be an issue. So, whenever we did not have adequate wind
to sail, we motor
sailed or motored at 1550 RPM's, made RO water
and went where we wanted to go. Since we have fuel
capacity of 400 gallons and water
capacity of 200 gallons, we were making 20 gallons of RO water each hour at a cost of 1.1GPH of diesel fuel
. We "made" water until the vents overflowed, then washed the boat with RO water and made our anchorage.
We often shared our water with the pleasant Mexican villagers who insisted on sharing their langusta, (lobster).
In addition to the 8KW main engine driven generator, we have a 5KW genset
that will drive the watermaker
. Often at a clean water anchorage, we would top off our fresh water tanks
Of course this will depend on you boat, engine size, placement, etc.
PM if we can help.
Tom & Bobbie Vandiver, Cal
Cruising 46, SATORI, Bayou Chico, FL