This dive site, Koh Haa Yai #5, also known as The Cathedral, is the largest island in the Koh Haa group. It's famous for its unique underwater topography, featuring three significant caverns on its southwest side. Two of these caverns are interconnected by a large, round swim-through, creating an engaging and scenic route for divers. The largest cavern is aptly named The Cathedral due to its impressive size and structure, offering a majestic experience as divers explore its depths. There is no specific history or story provided, but its natural formations are the main draw.
Marine life at Koh Haa Yai #5 is diverse and captivating. Divers can expect to find fascinating small creatures such as the elusive harlequin shrimps and the well-camouflaged leafy ghost pipefish, making it a paradise for macro enthusiasts. The rocky crevices and cracks are home to spiny lobsters. Large gorgonian sea fans adorn the landscape, adding to the vibrant underwater scenery. Occasionally, lucky divers might even spot a whale shark cruising along the western side of the island.
The best time to visit this dive site for optimal conditions is typically during Thailand's dry season, from November to April, when visibility is generally excellent. The relatively shallow maximum depth of 19 meters and an average depth of 9 meters make it suitable for both divers and freedivers, with the caverns offering an exciting challenge for those comfortable with overhead environments. Snorkelers can also enjoy the shallower areas around the island.
