Meet the site
Prison Island is a tiny sandy cay on the eastern side of the Cocos lagoon, visited by lagoon tours for its history and its nursery reefs. The name dates from the early settlement era of the 19th century, and local guides tell several versions of how it came about; Cocos Blue Charters' half-day trips include the island as a historical site. The official tourism snorkelling feature describes the cay as recently cleared of coconut palms and surrounded by a juvenile fish nursery, and the official snorkelling guide groups it with the Broccoli Patches as hidden gems of the eastern atoll reached with a local skipper. Snorkelling is in shallow water around the cay, over coral patches, sand and seagrass where juvenile reef fish shelter before moving out to the reef; small blacktip reef sharks, turtles, parrotfish and wrasse are common. Offshore, the Prison Gardens dive site uses the deeper reef nearby. The snorkel is easy, suits families, and is often combined on the same trip with Horsburgh Island and the Phaeton wreck, giving a sampler of the lagoon's history and marine life. Because it is out on the eastern side, it is best visited on calm days. Stories of the island's history vary, and visitors should hear them from the local guides. Tour groups are small, and the skippers know the lagoon's sandbanks and channels intimately – important on the eastern side, where shallow flats and coral heads make navigation tricky for anyone unfamiliar with the lagoon. Bring a hat, reef shoes and plenty of water: the cay has no shade to speak of, and the reflection off white sand and water intensifies the sun.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Prison Island is recorded as Island in Cocos (Keeling) Islands. The listed access is boat (day trip). Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
Topics flagged by the stored research
These are questions prompted by the existing notes, not a verified or complete hazard assessment.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
Historical access notes exist for this record, but have not been independently verified for current use. Request current directions from the operator or site manager rather than following an old entry description.
Questions, answered
Is Prison Island suitable for my certification?
The record lists Snorkel/Any. That does not establish suitability for every route or day. Share your training, recent experience and equipment needs with the operator and ask about the specific proposed dive.
Can I book Prison Island through YouDive?
YouDive is an independent research directory. Contact an operator directly to confirm whether it currently runs the trip, the inclusions and the booking terms.
What you might see
Juvenile reef fish, juvenile blacktip reef sharks, green turtles, parrotfish, wrasse, giant clams, hard corals
Location
Small sandy cay on the eastern side of the lagoon, south of Direction Island, visited by lagoon tours for snorkelling over shallow nursery reefs.
Facilities nearby
None on the island; tour boats supply water and refreshments.
Before you make plans
Conditions, access and operator schedules can change. This is a location guide, not a dive plan. Ask a local operator about current conditions and suitability for your training and experience.
Sources & further reading
cocoskeelingislands.com.aucocoskeelingislands.com.auaustraliantraveller.comwesternaustralia.comRecord updated 27 Sept 2026. Source claims are being reviewed.
