Meet the site
Cockatoo and Mudlark are a second pair of 20 m vessels in the Fenton Patches field, scuttled side by side as fish habitat in about 25 m of water. They sit on the western margin of the reef area, roughly 1.8 km west of Marchart 3, and like Galah and Heron they are known mainly to anglers, with only occasional visits by divers.
The names suggest ex-government or port workboats, but their history is not documented in the published reef lists, which describe them only as '2 x 20 m vessels'. What matters to divers is that they provide two adjacent steel hulls that have been colonised for many years by sponges, soft corals, sea whips and oysters, and that hold good numbers of fish.
Expect golden snapper and saddletail snapper in the shelter of the hulls, estuary cod and black jewfish in any cavity, and schools of fusiliers and baitfish above, which in turn draw trevally, queenfish and mackerel. Because the two hulls are close together, the gap between them acts as a sheltered gutter where fish congregate when the tide is running.
The site is dived as a simple exterior circuit of both vessels. With 20–25 m depths and a short slack window, there is time for a relaxed tour of both hulls on a single tank. Visibility is typically slightly lower on the western side of Fenton Patches when the tide is carrying sediment out of Darwin Harbour, so plan it for the best neap days.
It suits advanced divers who want to add less-visited Fenton sites to their log, and anglers-turned-divers curious to see what is holding the fish they target.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
Cockatoo and Mudlark Artificial Reef is recorded as Wreck in Darwin Offshore & Artificial Reefs. 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.
- Current and timing
- Ask how the operator assesses the current window for the actual route. Historical tide notes are not a departure instruction.
- Other water users
- Ask about vessel activity, exclusion areas and the agreed surface arrangements.
- Lines and obstructions
- Discuss any known entanglement concerns and the suitability of the planned area.
- Planned depth
- Confirm the intended route and training requirements; the recorded maximum is not a target.
- Water movement
- Ask how swell and local exposure affect the proposed entry, exit and route.
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 Cockatoo and Mudlark Artificial 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 Cockatoo and Mudlark Artificial 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
Golden snapper, saddletail snapper, estuary cod, black jewfish, trevally, queenfish, Spanish mackerel, fusiliers, baitfish, sponges, soft corals
Location
Two 20 m vessels scuttled side by side on the western edge of the Fenton Patches reef field (12°10.097'S 130°39.732'E).
Facilities nearby
Departure facilities at Cullen Bay Marina (fuel, ramp, toilets, cafes) and Dinah Beach; air fills in Darwin only.
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
nt.gov.aumarinelife.org.auRecord updated 26 Sept 2026. Source claims are being reviewed.
