Meet the site
Ashmore Reef lies in the Timor Sea about 320 km off the Kimberley coast, in the Commonwealth Territory of Ashmore and Cartier Islands. It is a biodiversity hotspot with about 833 fish species, 433 molluscs and 178 echinoderms recorded, around 100,000 breeding seabirds, and green turtle nesting; shark numbers have recovered significantly since 2004. It was historically famous for sea snake diversity.
The reef lies within the 1974 Australia–Indonesia MOU Box, where traditional Indonesian fishers have access, and divingwawrecks notes numerous small Indonesian perahu sunk by authorities for illegal fishing or people smuggling, scattered through the shallows. Both Ashmore Reef and Cartier Island marine parks are strict nature reserves except a recreational use zone around West Island; entry to sanctuary zones requires approval.
Kimberley diving context: the Kimberley coast between Broome and Wyndham is one of the least-dived coastlines in Australia. Huge tides (up to 10–11 m), turbid inshore water, saltwater crocodiles around the islands and rivers, and large sharks mean that inshore diving is generally discouraged by experienced local boaters, and expedition cruise ships mostly offer snorkelling or Zodiac excursions rather than scuba. The serious diving is offshore, on atolls and island reefs far from river run-off, visited on a handful of liveaboard departures a year from Broome or Darwin. Medical help is many hours away; divers should be conservative and carry DAN or equivalent evacuation cover.
Planning notes: Advanced Open Water certification is recommended and the site is rated advanced. Expect to spend most of the dive around 12 m, with a maximum of about 30 m. It can only be reached on a multi-day expedition or liveaboard, so it is usually one of several sites dived on the trip and choices are made by the crew on the day. Currents are significant, so timing around the tide is part of the plan. Best season: September–November (calmest window). Traffic: remote/expedition only.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Ashmore Reef is recorded as Reef in Ashmore Reef. The listed access is boat (multi-day/liveaboard). Confirm the actual meeting point, route and permission to visit; a map pin does not establish any of these.
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 Ashmore Reef suitable for my certification?
The record lists Advanced Open Water. 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 Ashmore Reef 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
833 fish species, sharks (recovering), sea snakes, green turtles, seabirds, corals, molluscs
Location
Large reef in the Territory of Ashmore and Cartier Islands, about 320 km off the north-west Kimberley coast and 170 km south of Rote (Indonesia); a Commonwealth marine park.
Facilities nearby
None – remote; all services on the vessel.
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
en.wikipedia.orgdivingwawrecks.comRecord updated 26 Sept 2026. Source claims are being reviewed.