Gato Island is a reef, wall and cave dive site in the Philippines, in the Visayan Sea. It is reached by boat. The signature feature is a 30-metre swim-through tunnel connecting both sides of the rocky islet. The island lies within the Monad Shoal and Gato Island shark and ray sanctuary. It was designated a sea snake and fish sanctuary in 1997, with the protected zone expanded in 2001 to a 2-nautical-mile radius managed by the municipal government. Banded sea kraits and whitetip reef sharks are resident, along with nudibranchs. Blacktip reef sharks, pygmy seahorses, frogfish, scorpionfish, moray eels, seahorses, pipefish and Spanish dancers are occasionally seen.