Koh Lipe sits at the southern edge of Tarutao National Marine Park, Thailand's first designated marine reserve, established in 1974 to protect 51 islands across 1,490 square kilometres of the Andaman Sea. The park encompasses more than 25 percent of Thailand's coral diversity, with reef systems extending from shallow lagoons to drop-offs beyond 30 metres. Hard corals dominate the eastern channels, while soft corals and sea fans cluster along western slopes exposed to monsoon currents. The reserve recorded 25 species of hard coral and 108 reef fish species in its baseline biodiversity survey, numbers that have grown as enforcement reduced dynamite fishing and anchor damage. Snorkeling tours from Koh Lipe follow two main trajectories. Eastern routes reach Koh Adang, Koh Rawi, and the Jabang cluster, where granite boulders create swim-throughs and sheltered bays hold staghorn thickets. Western itineraries trace the outer arc toward Koh Hin Ngam and Koh Yang, exposed sites with stronger currents and pelagic visitors. Visibility averages 15 to 25 metres during the November-to-April high season, dropping to 8 to 12 metres during the monsoon transition. Water temperature holds steady at 28 to 30 degrees Celsius year-round. Longtail boats remain the standard vessel, their shallow draft allowing beach landings and navigation through reef passes inaccessible to larger craft. The 200-baht conservation fee, valid for five days, funds ranger patrols and mooring-buoy installation. That fee applies to all visitors entering marine park zones, collected at departure points or aboard vessels. Morning departures between 08:30 and 10:00 reach outer sites before midday surface chop builds. Half-day tours typically include two or three snorkel stops over four hours, while full-day itineraries add a beach lunch and extend to five or six sites. Guides carry basic first aid and spare masks, though rental quality varies by operator. The park prohibits fish feeding, coral touching, and single-use plastics aboard permitted vessels. Seasonal closures occasionally affect specific sites during nesting periods for sea turtles, announced on park notice boards at Walking Street. Koh Lipe snorkeling tours operate daily except during severe weather advisories, with operators monitoring swell forecasts from the Thai Meteorological Department. Most excursions limit group size to 10 or 12 passengers per boat to reduce reef impact and maintain guide-to-guest ratios. The island's compact geography means no snorkel site lies more than 45 minutes from shore, allowing flexible itineraries that adjust to conditions.