The SS Cooma was a 3,936-ton coastal passenger steamer that grounded on North Reef, at the northern end of the Capricorn Group, in 1926. The ship was subsequently gutted by fire, and her remains now lie in about 5 m of water as a jumble of metal slowly being covered by coral. Despite the damage, the main mechanical components are still recognisable.

Divers and snorkellers can identify the boiler, propeller shaft, hull plates and the triple-expansion steam engine among the wreckage, which gives the site genuine historical interest. Coral growth and fish life have colonised the metal, and the structure provides shelter on the reef flat for reef fish and invertebrates. North Reef is also home to one of Queensland's historic lighthouses, and the reef's northern tip includes a tidal channel known for manta rays.

Together these features make it a worthwhile stop for private boats and liveaboards passing through the northern Capricorn Group. The shallow depth means the wreck can be enjoyed by Open Water divers and snorkellers alike, but only in calm weather, as surge on the reef is strong whenever swell is running. As a historic wreck, the Cooma is protected under the Underwater Cultural Heritage Act 2018: look but do not remove or disturb anything.

The Cooma is one of the larger shipwrecks in the Capricorn Group and a reminder of the navigational hazards these reefs posed to coastal shipping. Snorkellers can see much of the wreckage from the surface at high tide on a calm day, making it a good family stop.

The Capricorn Group lies 60-100 km north-east of Gladstone. Private boats launch from Gladstone Marina (Bryan Jordan Drive; ramps, fuel and trailer parking) and cross the shipping approaches and open water, typically 2-4 hours depending on vessel and destination; the Capricorn Bunker liveaboards that occasionally visit depart Gladstone or Yeppoon (Rosslyn Bay) and anchor overnight in the lee of the cays. Camping on the national park cays requires a QPWS permit and a camper transfer or private vessel.

North Reef, with its historic lighthouse, is at the northern end of the Capricorn Group about 70 km north-east of Gladstone. Anchor off the reef in calm weather and dive or snorkel the shallow wreckage at high tide.

The Capricorn cays are exposed to the south-east trades (often 15-25 knots April-September), which make the Gladstone crossing rough and restrict diving to the lee (north-western) sides. The calmest windows are typically September-December and March-April. Northerlies in spring and summer reverse the sheltered sides.

Tidal currents run strongly around reef edges and channels on springs. Cyclone season November-April. The wreck lies in shallow water on the reef, so any swell causes strong surge; dive only in calm conditions around high tide.

Anchor off the reef, swim in to the wreckage and move slowly across it, identifying the boilers, propeller shaft, hull plates and triple-expansion engine. Keep off sharp metal and stay out of any enclosed spaces.

No daily operator. Occasional liveaboard itineraries (for example the 8-diver MV Adori run by Professional Dive Services, 4 days/3 nights from Yeppoon) and fishing/snorkel charters such as Eastern Voyager visit the Capricorn cays; otherwise private boats and camping groups only.