Pelagic Blackwater Night Dive

This site sits off the Kona coast of the Big Island of Hawaii, in deep open water where the ocean floor drops out of reach at around 1219 metres. Blackwater diving here takes place after dark over that deep water column, with divers drifting on a line away from any reef or bottom reference, watching for the migrating deep-sea larvae and small pelagic creatures that rise toward the surface at night. The listed depth reflects the seafloor far beneath the dive rather than the depth divers actually reach, since the dive itself is conducted in the shallow part of the water column. It is rated technical, given the open-ocean setting, the dark conditions, and the lack of any fixed reference point beyond the descent line.

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

• Thin-shelled Rock CrabGrapsus tenuicrustatusReported here · unconfirmed
• Spinner DolphinStenella longirostrisReported here · unconfirmed
• Shingle UrchinColobocentrotus (Podophora) atratusReported here · unconfirmed
• Indo-Pacific Rock-boring UrchinEchinometra mathaeiReported here · unconfirmed
• Yellow TangZebrasoma flavescensReported here · unconfirmed
• Red Pencil UrchinHeterocentrotus mamillatusReported here · unconfirmed