Big Mushroom

Big Mushroom at Green Island takes its delightful name from a massive underwater coral formation that rises from the seabed like an oversized fungus, its broad, rounded cap extending outward from a narrower stem to create one of the most distinctive and recognizable natural formations in Taiwan's diving landscape. This beginner-friendly site allows divers at all levels to appreciate this geological and biological wonder in the clear, warm waters that make Green Island one of Asia's premier dive destinations. The mushroom formation is an ancient coral structure of impressive dimensions, its rounded profile the result of decades of coral growth that has proceeded most vigorously on the upper surfaces exposed to the best light and current conditions. The overhanging edges of the cap create sheltered zones beneath, where shade-tolerant organisms thrive in conditions different from those above. This microhabitat diversity within a single structure makes Big Mushroom a site where close inspection is richly rewarded, with different communities of species inhabiting the sunny upper surfaces and the shadowed undersides. On the upper surface of the mushroom, a mature coral community has developed over many years in conditions that Green Island's position in the Kuroshio Current provides. Hard corals in various growth forms, from the branching Acropora tables that reach toward the light to the massive brain and star corals that dominate the flatter areas, create a complex three-dimensional community above the formation's central rim. Fish populations concentrate around and above the mushroom, using the structure as a territorial base and feeding station in the nutrient-rich current that flows past. The undersurface of the mushroom cap, in perpetual shade, supports a completely different biological community. Sponges and soft corals that cannot compete with the photosynthetic hard corals in brighter conditions thrive here, their vivid colors illuminated by divers' torches in a display that reveals the true richness of the site. Lobster and other crustaceans take shelter in the shaded spaces, emerging at night to feed on the reef. Green Island's setting in the Kuroshio Current creates the exceptional water quality and clarity that makes diving here so rewarding. The visibility that typically characterizes Green Island sites allows Big Mushroom to be appreciated from a distance before close inspection, giving divers the full visual impact of the formation's unusual shape before they move in for detailed observation. Water temperatures remain warm year-round thanks to the current, making Big Mushroom diveable in comfort across all seasons. Big Mushroom captures the imaginative spirit of underwater exploration, where natural formations of unexpected and whimsical shapes make the reef feel like a place of discovery and wonder. For beginner divers building their first memories of the underwater world, this iconic Green Island formation provides an encounter that perfectly blends accessibility with genuine natural spectacle.