Similan Dive Center is a diving specialist and booking agency based in Khao Lak, Thailand, operating since 2004. The team arranges daily diving day trips from Khao Lak to the Similan Islands, Koh Bon, Koh Tachai, Richelieu Rock, Surin Islands and the Boonsung Wreck, plus SSI and PADI courses, and books multi-day liveaboard trips (2 to 5 days) on a range of partner vessels. The center also runs its own dive and snorkel gear shop in Khao Lak, stocking brands such as Mares, Seac, Ocean Dynamics and Huub. The diving season runs from October to May, with the best visibility between December and April when manta rays and whale sharks are more frequently sighted.