Best thing to do is go to the airport hotel. There is a nice pool, with good shade, and alcoholic drinks are served. You can pay for a daypass - I think around $20. I disagree about the traders hotel, unless you want to have a stroll around Male. The pool is small but nice at traders, but the pool area is very hot, as it is exposed on the rooftop. There is not alcohol, and I'm not sure that you can buy a day pass.

But you can also do that from the airport island - 10 minute boat trip free on the hotel boat, or about a dollar on the local boat service, leaving every 10 mins.