Endeavour Reef is where European contact with this coast nearly ended in disaster. At 11 pm on 11 June 1770, Lieutenant James Cook's HMB Endeavour struck the south-eastern end of the reef; to refloat the ship the crew threw overboard six cannons, iron and stone ballast and other heavy gear, and the damaged vessel limped to the Endeavour River, where Cook spent seven weeks repairing it on the site of present-day Cooktown. Cook named the reef Endeavour Rocks.

In 1969 an American-led search located all six cannons and the ballast; the cannons are now divided between the National Museum of Australia, the Cooktown museum, the Australian National Maritime Museum, Te Papa in Wellington and Royal Museums Greenwich. The reef is about 7 km long, running east-west, roughly 6 km south-east of the Hope Islands and 12 km from the mainland. As a dive, it is a remote mid-shelf reef rather than a historic wreck site: nothing of the Endeavour remains in place, and the site's significance is in its story.

Guides describe hard coral formations and bommies, reef sharks along the drop-offs, giant clams and schools of fish, with clearer water in the dry season and murkier conditions in the wet when river runoff reaches the reef. Strong currents run around the reef edges. There is no regular dive operator, so divers need a charter or private boat and must be self-sufficient.

It suits experienced divers with a sense of history and a tolerance for logistics. A visit is best combined with Cooktown's James Cook Museum, where one of the recovered cannons and the Endeavour's anchor are displayed.

Cooktown is about 330 km north of Cairns by the sealed Mulligan Highway (about 4.5 hours) or reached by air. Endeavour Reef lies south-east of Cooktown; the boat run from Cooktown Harbour at the mouth of the Endeavour River takes about 1.5-2.5 hours depending on sea conditions. There is no scheduled dive boat: go with a local charter (Cooktown Reef Charters runs a 42 ft vessel for fishing and reef sightseeing – confirm diving in advance) or a well-equipped private boat launched at the Cooktown boat ramp.

Divers must bring their own gear; there is no dive shop in Cooktown, so fills must be arranged in Cairns or Port Douglas.

Cooktown's reefs are exposed to the south-east trade winds, which blow strongly for much of April-September; calm windows are most likely from September to December. Visibility is best in the dry season (May-October) and drops sharply in the wet season when the Endeavour and Annan rivers flood. Box jellyfish and Irukandji are present roughly October-May, and the cyclone season runs November-April.

Currents run hard around reef edges on spring tides.

Anchor in sand in the lee of the reef, dive the reef edge and bommies at 5-15 m with the reef on one side, turning at a third of your gas, and return along the edge for a safety stop near the boat. Watch the current on the reef edges.

No regular dive operator – Cooktown Reef Charters (fishing/sightseeing, enquire about diving) or private boats from Cooktown; occasionally visited on northern liveaboard itineraries