A friend's Bene 36.7 has an engine box blower/fan that runs when the engine runs... keeps the heat down and tends to remove engine smell too.. I'm considering adding same to our boat.
As mentioned some time back, an off-delay function on such a fan would be a nice feature.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)