숲섬

Supseom (숲섬), or Forest Island, is an advanced dive site off southern Jeju reaching 40 metres depth, named for the dense vegetation covering this small volcanic islet. Beneath the surface, the island's basalt foundations create one of the most dramatic wall diving experiences in Korean waters. The underwater topography features sheer volcanic walls that plunge from the shallow reef crest into the deep blue, with horizontal bands of different volcanic rock types creating a striking geological cross-section. The walls are punctuated by ledges, overhangs, and small caverns at various depths, each hosting distinct communities of marine life adapted to their specific depth zone and light level. Supseom's walls are renowned for their spectacular soft coral coverage. Dendronephthya colonies in brilliant reds, yellows, and purples drape from overhangs and ledges, creating some of the most photogenic underwater scenery in South Korea. The soft corals are at their most vibrant between March and June, when cooler water temperatures and increased nutrient availability trigger peak growth. The site's deep profile and current exposure attract larger marine species. Schools of yellowtail amberjack cruise along the wall, while groupers of impressive size inhabit the deeper ledges. Octopuses are common residents, their dens identifiable by the accumulation of shell debris at the entrance. Occasional encounters with sea turtles and even whale sharks have been reported during the summer months when the warm Kuroshio Current reaches its greatest influence. Current management is crucial at Supseom, as tidal flows can be strong and unpredictable. Most dives are conducted as drift dives, with experienced boat crews tracking divers' surface marker buoys. The depth and current combination mean this site is strictly for experienced divers with appropriate deep diving certifications. Water temperatures range from 13 to 25 degrees Celsius across the seasons, with a drysuit recommended for visits outside of July to September. Visibility can be exceptional, reaching 25 to 30 metres during winter months.