Iron kentledge (pig-iron ballast) recovered from Endeavour Reef, Queensland. Jettisoned when ENDEAVOUR struck Endeavour Reef on 11 June 1770.

After Cook’s landing at Botany Bay, ENDEAVOUR continued northwards up the east coast of Australia. On the night of 11 June 1770, at 11pm, the ship struck a reef (now called Endeavour Reef) about 13 miles off the coast of what is now Queensland, north and slightly east, of Cape Tribulation.

The ship was taking water and was grinding hard on the coral. In the morning Cook ordered the jettisoning of condemned stores, pig-iron kentledge and stone ballast, and six guns (all they had on deck), in an effort to lighten the vessel. Even so, ENDEAVOUR was stuck on the reef for over twenty-three hours and it was not until 10:20 pm on 12 June, that she was floated off. To reduce the amount of water the ship was taking in, a sail was sewn with hair, oakum and wool, and passed under her bows to “fother” the hole. This emergency treatment plus good fortune in that a lump of coral broke off and remained wedged in the hull blocking water ingress, saved the ship.

ENDEAVOUR then took refuge at a river which was named after the bark, at the site of the later town of Cooktown, from 18 June until 5 August, during which time the vessel was beached, and the damaged timbers replaced and repaired. Upon leaving the river the ship negotiated, with difficulty, the remaining hazards of the reef-strewn channel, and made for open water through Cook’s Passage, just north of Lizard Island. Cook sailed on to claim the east coast of Australia for England.