Beneath the drift dive at Coconut Point lies a submarine cave system that most visiting divers never see. It was documented during a 2014 scientific survey of Christmas Island's submarine and anchialine caves (Tan, Naruse, Fujita and Tan, Raffles Bulletin of Zoology), which recorded its position and described a cave system with a narrow mouth about 3 m across at 15 m, affected by strong surge during tidal change.

Christmas Island's coastline is honeycombed with caves formed when sea levels were lower, and many of them extend back into the island's limestone to anchialine pools where fresh groundwater sits over seawater. These caves host specialised crustaceans – crabs, shrimps and lobsters – some known only from the island, and the survey team was collecting and documenting that fauna. Coconut Point's cave was one of the sites on their list, alongside Daniel Roux, Thunderdome, Thundercliff and West White Beach caves.

This is not a recreational dive. A 3 m restriction at 15 m, combined with surge that can push and pull divers through the mouth at tide changes, makes it a serious overhead environment, and there is no published account of recreational visits. Anyone intending to enter it would need full cave training, a local guide or operator's support, and a slack-water, flat-calm window.

It is included here as a named, documented feature rather than as a recommended dive. For recreational divers, the reef and eel gardens above make up the Coconut Point drift, and the island's accessible cave experiences are at Thundercliff, West White Beach Cave, Boat Cave and, with a guide, Daniel Roux and Thunderdome.

Fly from Perth (about 4 hours, two to three flights a week, some via Cocos Islands) and hire a car – there is no public transport. Both dive centres are in The Settlement and launch their boats from the jetty/boat ramp at Flying Fish Cove, normally at about 8 am for a two-dive morning trip. From the cove the boat runs east along the Settlement shoreline along the coast for roughly about 10 minutes to Coconut Point.

There is no land access to the dive, and the vertical sea cliffs mean no exit other than the boat. Operators choose sites on the morning according to swell and wind.

On the north-east corner of the island, off The Settlement. Sheltered from the south-east trade winds (roughly April/May–November), when it is usually calm, but exposed to northerly and north-westerly monsoon swell from about December to March/April; Extra Divers report February–April as peak swell season when boat diving is often cancelled. The corner catches currents that sweep around the island, so conditions can change within a single dive.

Visibility is normally 25–40 m, lower after heavy rain and during red crab spawning (October–January), which is also when whale sharks are most likely. The narrow entrance experiences strong surge during tidal change – only approachable at slack water in flat conditions.

Only for cave-trained teams: descend at slack water to the 3 m mouth at 15 m, run a primary line from outside, and follow the thirds rule strictly; abort at any sign of surge. Recreational divers should view the entrance from outside during the Coconut Point drift only.

Full cave certification (CDAA Penetration grade or equivalent), continuous guideline, redundant gas and lights, slack water only; consider sidemount for the restriction. Consult Parks Australia regarding research sensitivities of anchialine fauna.

No regular operator – surveyed by scientific cave-diving teams; not part of Extra Divers' or Wet'n'Dry's normal Coconut Point drift. Any visit must be arranged specially with an operator and cave-qualified guide.