We are in Kuwait, (where it is hotter than anywhere else!) and we bought a WANSA unit from Al Ghanim (Excite) Electronics
. We only ever use it in the Marina, as no matter how hot the desert gets, it's always 10 degrees cooler at sea. Having said that, we do get enough power from our solar panels
that we could run a/c from it at sea, but prefer to keep it for the fridge!!
In our last yacht, we installed simple electric
(car) fans to transfer air between cabins - it worked a treat.
It's essential to have a good shade system rigged up, of course!