龍洞灣4號潛點-和美國小

龍洞4號潛點, known in English as Longdong No.4, is an intermediate dive site within the Long Dong Bay complex on Taiwan's northeastern coast, located near the village of Hepingshi Elementary School and descending to twenty-six meters through some of the most interesting mixed-current reef terrain available within easy reach of Taipei. This site showcases the geological and biological variety that makes Long Dong Bay a destination of genuine diving quality rather than simply a convenient urban escape. The rocky volcanic formations that define Long Dong Bay's underwater landscape are particularly well-expressed at this site, with the characteristic angular geometry of the rock creating walls, ridges, and boulder fields that provide exceptional habitat diversity within a moderate depth range. The twenty-six meter maximum depth allows comfortable exploration of the full range of reef zones, from the well-lit shallows where photosynthetic organisms dominate to the deeper sections where encrusting sponges and soft corals claim the surfaces that harder reef builders cannot colonize effectively. Long Dong Bay's position at the biogeographic overlap between tropical and temperate Pacific marine zones creates the distinctive species assemblage that makes this site biologically interesting beyond its aesthetic appeal. Tropical reef fish from Kuroshio-transported larvae share the reef with cooler-water species more typical of northern Pacific shores, creating combinations that surprise experienced divers familiar with either tropical or temperate diving but not their overlap. This meeting of biogeographic zones is particularly pronounced at intermediate depths like those of Longdong No.4, where conditions allow both communities to be present simultaneously. The site's sponge and soft coral community deserves particular mention. Long Dong Bay's volcanic rock substrate and the complex current patterns that flow through the bay create ideal conditions for the encrusting and soft coral communities that are the site's biological signature. Multiple sponge species coat the rock surfaces in vivid colors, while alcyonarian soft corals in various forms add their flowing, tree-like structures to the reef's visual landscape. For macro photographers, this soft-bodied invertebrate community provides extraordinary subject matter, with nudibranchs grazing on specific sponge species and small crustaceans hiding within the coral's structural complexity. Current at Longdong No.4 can be significant during certain tidal phases, reflecting the site's exposure to the oceanographic forces that make Long Dong Bay both challenging and productive. The current brings the nutrients that sustain the site's biological richness but also demands awareness and experience from divers who want to make the most of the site without exhausting themselves fighting the flow. Understanding the current patterns around the bay, including the best times and approaches for each site, is part of the local knowledge that experienced Long Dong dive operators provide. Longdong No.4 represents a mature, substantive intermediate dive site that rewards repeated exploration. Its combination of volcanic terrain, biogeographic diversity, and excellent marine growth makes it a cornerstone of Long Dong Bay diving.