The addition of 12V sockets in strategic locations to power electric fans has proved to be a real winner. When anchored in the tropics or when the only shore power is American 60Hz precluding the use of one of the AC units, the cooling provided by the fans is a real boon.
We have found that the traditional axial fan has its place but that they tend to be noisy and fragile.
The centrifugal fans however are sturdy, two speed, more compact and will sit on a shelf, out of the way ready to be switched on whenever the need arises. You will find them very cheap on Amazon.