I f you rent a hotel room, they will let you use the pool for an indoor swim party. Check in your area. Or they may just rent you the pool for a few hours. We just did a luau and I played a game I called "Hawaiian Vacation" I had 2 kids stand at the front of the room with a bucket of dress up stuff next to each of them - a leigh, a beach ball, giant sunglasses, a calypso hat, etc. All the kids were in 2 lines in front of them. The 2 teams had to do a relay race to dress thier guy up for Hwaiisn vacation the fastest. They had so much fun they played over and over with a differant kid getting dressed up each time.
Also you cant go wrong with a pinata.