We had a 12 m sloop
DIVA, put a FLEMING
GLOBAL 501 wind vane
on the retrousse stern and sailed thousands of miles all over the Pacific with it...fantastic !
Only problem we had was the pulleys breaking (Ronstan), replaced them with Garhauer and no problem......you do need to change the vanes tho...the standard is good to 15 knots, above that you need to change to the smaller one...we kept about 4 or 5 of the standard one and 3 or 4 of the small one on board....
But absolutely wonderful if you have the boat balanced, not too much headsail...they always wander unlike an autopilot
, but I would for a boat of 13m or less, recommend it without hesitation...
They don't need feeding, don't use electricity, and don't complain...well not much !