so I tried to design in the efficiency. The autopilot is a Raymarine X30 using the Jefa geared steering servo. Sailing, if I balance the boat well its pretty good. We sailed about 22 hours dead down wind in a seaway, and under those conditions it was using more like 4 amps average.

I was appalled at how bad the fans sold for yachts are, so I got a bunch of 24V brushless DC cooling fans (like what's used to cool computer enclosures) and we made nice cherry boxes for them and mounted them on RAM mounts. They draw about 180 mA each on high (100 on low), and put out a decent breeze. About $18 apiece, and 50,000 hour MTBF. I'll have to see how well they hold up on the boat - I am just installing them now. Lake Ontario this summer has been worse than the tropics - all the heat, humidity, and bugs without the trade wind, view, or charm. Seems to be cooling down as we move northeast though.

I reserved space for a genset, but the economics of it just didn't scan: salesman kept telling me to buy their genset so I wouldn't wear out my main propulsion engine. Only the genset cost about 30% more than the main propulsion engine, along with double the maintenance and half the reliability. When I point this out they shrug their shoulders. Probably makes sense on a larger boat, but not on mine. Instead, I installed the 7KW alternator on the main engine and the solar cells.