Meet the site
The Mauna Loa was a 5,436-ton American cargo ship built by the Los Angeles Shipbuilding and Dry Dock Company at San Pedro in 1919: a 125 m, two-deck, two-masted steamer with an oil-fired triple-expansion engine. Like the Meigs she was in Darwin with the convoy bound for Timor. While at anchor on 19 February 1942 she was hit by two bombs that went down an open hatch, starting fires and breaking her back, and she sank quickly. Sources differ on casualties: DSAC records five dead from a crew of 38, while other accounts say none of her crew or passengers was injured. The 19 February 1942 raids - two waves of Japanese carrier and land-based aircraft, the first and heaviest attack ever made on mainland Australia - sank eight ships in the harbour and killed more than 230 people. In 1959-60 the Japanese firm Fujita Salvage cut most of the wrecks down to or below the waterline for scrap, so what divers find today is usually the lower hull, machinery that was too heavy to lift, and the cargo that the salvors were not permitted to remove. Mauna Loa was heavily salvaged in 1960 and today lies about 18 m down as a twisted, broken lower hull on a sand and silt bottom. The salvors were barred from taking the American cargo, and the holds still contain the war materiel she was carrying: military trucks, Bren gun carriers, a Harley-Davidson motorcycle and large quantities of .303 and .50-calibre ammunition. Picking out recognisable pieces in the gloom is the appeal of the dive. It is often combined with the Meigs on the same neap-tide window, and the pair give the clearest picture of what the Timor convoy was carrying. The 2015 multibeam survey of the harbour produced detailed images of the site showing its twisted deck littered with ammunition, motorcycles and gun carriers. Suitable for Open Water divers with some low-visibility experience; a good torch makes a big difference.
Research this site before booking Stored site notes may be historical. These questions highlight gaps without turning old instructions into a current dive plan.
SS Mauna Loa 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 SS Mauna Loa 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 SS Mauna Loa 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
Estuary cod, golden snapper, jewfish, batfish, trevally, sweetlip, sea snakes, sponges and gorgonians
Location
Darwin Harbour anchorage about 3 km from the Darwin wharf and roughly 1 km from the USAT Meigs.
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
dsac.com.aumarinelife.org.auen.wikipedia.orgabc.net.aunt.gov.auRecord updated 27 Sept 2026. Source claims are being reviewed.