Thanks for all the replies.
I have fitted a fan. An Atwood 4000 bilge
blower. It puts out a lot of air. It's like putting your hand out of the window in a car on the freeway.
I am still on the hard
. Launch tomorrow
I have pulled up the new chain a few times and the motor temperature is noticeably lower with the fan going. Hauling up the chain and anchor only 4-5m with no force is not much of a test of an anchor winch, but if keeps the temperature lower with this low load, it should make more difference when the motor is near its limits.
Having spent a few days curled up in the anchor locker, installing the new winch, I can testify it gets hot in there. There is is no deck insulation
in the anchor locker unlike the rest of the boat.
The blower was cheap
and simple to install. The fan noise
has the added benefit that it alerts me if I forget to turn the anchor winch off.