Bali Hai Pier has dispatched vessels to the Gulf of Thailand's island belt since 1982, when Pattaya's shoreline still wore the sleepy contours of a fishing port. The public ferry schedule — departing every thirty minutes from 06:30 to 17:30 daily — carries thirty baht fares unchanged for a decade, a relic of municipal subsidy in a city reborn as Southeast Asia's waterfront playground. Today the pier anchors a fleet of catamarans, speedboats and traditional longtails that thread a six-nautical-mile corridor between Pattaya Bay and the coral-fringed islands dotting the horizon. Koh Larn, the largest outcrop at four square kilometres, claims seven named beaches and a resident population of two thousand; Coral Island and Sak Island remain uninhabited save for daylight vendors and parasail operators. The three-island circuit — pioneered by commercial operators in the early 2000s — stitches together snorkelling reefs, white-sand coves and offshore platforms for parasailing and jet-ski runs, covering twelve nautical miles in a six-hour loop. The geology beneath these waters tells a deeper story. The gulf floor here slopes gently from fifteen to thirty metres, creating shallow plateaus where hard coral colonies — brain coral, staghorn, table coral — build reef systems visible from the surface. Visibility peaks between November and April, when northeast monsoons settle and plankton bloom recedes, revealing angelfish, parrotfish and moray eels threading the coral branches. Marine biologists map over two hundred fish species in this coastal zone, a biodiversity pocket sustained by the gulf's warm currents and the freshwater plume from the Chao Phraya River delta seventy kilometres north. Pattaya boat tour operators now run hybrid itineraries blending transit speed with onboard amenities: Thai buffet lunches served at sea, snorkel gear distributed mid-voyage, and UV-shaded upper decks for the two-hour round-trip crossing. The Sanctuary of Truth — a teak temple rising from the northern headland — appears on extended routes combining land and sea legs, though purists argue the islands alone justify the passage. Departure slots cluster in early morning to secure mooring space at Tawaen Beach and Samae Beach before tour groups converge after 10:00.