Meet the site
The NR Diemen is widely regarded as one of the most intact wrecks in Darwin Harbour and one of the easiest to enjoy. She was a 73 ft (about 20.5 m), 124-ton steel research trawler that broke from her moorings at Stokes Hill Wharf during Cyclone Tracy and drifted across the harbour before sinking near Mandorah. Cyclone Tracy crossed Darwin in the early hours of 25 December 1974 with gusts estimated at over 200 km/h, destroying most of the city and killing 66 people, many of them at sea. More than 20 vessels sank or were driven ashore in and around the harbour, and several of those wrecks now form a second, much more intact wreck trail beside the 1942 sites. She sits upright on a sloping sand bottom with her bow rammed into the shore facing west and her stern facing east in about 12 m. The top of the trawling gantry comes to within a metre or so of the surface at low tide and can be seen from a boat. Because of her east-west orientation the hull offers shelter from the tidal stream, and the wreck stays relatively clear of silt compared with the harbour's other sites. Fish life is some of the best in the harbour: black jewfish, groper, barracuda, trevally, mackerel, tuna and rock cod patrol the structure, and wobbegongs rest on the deck. With a maximum of 12 m, a recognisable ship shape and the chance of good fish encounters, the Diemen is the standard first wreck for newly certified divers in Darwin and a good training site, and it is also rewarding for photographers on the rare days of better visibility. The shallow gantry also gives snorkellers something to see on a clear neap.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
NR Diemen is recorded as Wreck in Darwin Harbour. 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.
- 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 NR Diemen suitable for my certification?
The record lists 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 NR Diemen 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
Black jewfish, groper (estuary cod), barracuda, trevally, Spanish mackerel, tuna, rock cod, wobbegong sharks, batfish
Location
On the sloping sandy shore about 1.2 km from Mandorah jetty on the western (Cox Peninsula) side of the harbour.
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
marinelife.org.audsac.com.auRecord updated 26 Sept 2026. Source claims are being reviewed.