I haven't stayed at the Marriott Kauai but have stayed at the Sheraton Kauai numerous times. The pool and beach are both great. Plenty of snorkels Boogie board etc to rent. The restaurant Rum Fire is one of my favorite restaurants on the island. That being said, the rooms are tired. They are totally clean and fine, but not as nice as other Hawaiian properties I have stayed at. If you go,' make sure to stay in one of the beach side buildings. He garden buildings are across the street and a bit far from everything.