No, you cannot swim in the actual waters of Marina Bay itself; the water is part of a reservoir system and is strictly for aesthetic and light recreational use (like the annual dragon boat races or floating light shows). However, the confusion often comes from the Marina Bay Sands Infinity Pool, which is the world's most famous rooftop pool overlooking the bay. You can only swim in this infinity pool if you are a registered guest of the Marina Bay Sands hotel; there are no "day passes" sold to the public for the pool area. If you aren't staying at the hotel, the closest you can get is the SkyPark Observation Deck, but it is separated by a fence from the swimmers. For those wanting to swim in natural waters in Singapore, you must head to the beaches of Sentosa Island or the East Coast Park, where the water is designated for public swimming and monitored for safety and quality.