House Reef (Sipadan-Kapalai)

Sipadan lies off the east coast of Sabah in Malaysian Borneo, a small oceanic island rising from a deep drop-off in the Celebes Sea, reached by boat from Semporna. The House Reef refers to the fringing reef right off the island itself, part of the broader Sipadan system long known for its steep walls and resident turtles, with green sea turtles among the species divers have reported here. Access to Sipadan is tightly controlled by permit, with divers usually based on Kapalai or Mabul nearby and boating over for the day. The House Reef is also a good spot for macro life, with divers reporting a range of nudibranchs including Anna's Chromodoris, Batangas Halgerda, Blue Dragon, Coi's Goniobranchus, Dusky Nembrotha, Geometric Goniobranchus, and Willan's Chromodoris, along with common lionfish tucked among the reef structure.

Confirmed by our research team, reported by independent divers, or observed nearby via iNaturalist — each entry is labelled with its source.

• Dusky NembrothaNembrotha kubaryanaReported here · unconfirmed
• Anna's ChromodorisChromodoris annaeReported here · unconfirmed
• Willan's ChromodorisChromodoris willaniReported here · unconfirmed
• Coi's GoniobranchusGoniobranchus coiReported here · unconfirmed
• Blue DragonPteraeolidia semperiReported here · unconfirmed
• Hypselodoris variobranchiaReported here · unconfirmed
• Green Sea TurtleChelonia mydasReported here · unconfirmed
• Geometric GoniobranchusGoniobranchus geometricusReported here · unconfirmed
• Batangas HalgerdaHalgerda batangasReported here · unconfirmed
• Common LionfishPterois volitansReported here · unconfirmed
• Whitetip Reef SharkTriaenodon obesusObserved near here · iNaturalist