This is a bigger and further island, but Mamutik is better for snorkeling.

Nice and clean beach, just 20 minutes from Kota Kinabalu. Snorkeling is alright with clean water and some fishes, not much corals though. Plenty of tiny jellyfish 😓

Plenty of Chinese and Korean tourists. Pack your lunch and drinks (maybe include tea as well) before going to the islands.

RM 30+ per person to go to two islands (different operators offer different packages). Snorkeling gear and life jacket included. Plenty of food stalls at the jetty as well.