The Capricorn and Bunker Cays form part of a distinct geomorphic province at the southern end of the Great Barrier Reef.

The sea level was much lower during the last ice age (at the end of the Pleistocene period) and the coastal plain on which today's reefs and cays developed was completely exposed.

[3] In 1803, Captain Eber Bunker of the whaling ship Albion was the first European to discover the region and gave his name to the southern group.

[4] The southern cays and reefs were first chartered between 1819 and 1821 by Lieutenant Phillip Parker King RN initially in the Mermaid and later in the Bathurst.

The main charting exercise for all the islands and reefs was carried out in 1843 under the command of Captain Francis Price Blackwood in HMS Fly which was accompanied by the Bramble.

The naturalist, Professor J. Beete Jukes, was on board the Fly and his published journal provides valuable information on some of the cays.

[5] The Governor Philip, which arrived on Saturday last, from Moreton Bay and Port Macquarie, has brought up the crew of the ship America, bound from Hobart Town to Batavia, which was unfortunately wrecked on a coral reef, on the Northern Loo Islands.

This disastrous occurrence took place about 1 o'clock in the morning of the 20th of June, when the vessel was running under three topsails and a foresail, in the midst of a black showery squall.

All the sails were immediately clewed up and stowed, the stream anchor stocked, and every exertion made to endeavour to heave off, but without effect; particularly as the darkness of the night and the heavy sea, rendered it quite impossible to lower a boat.

The following are some interesting particulars of the proceedings of the crew, from the time the vessel struck up to their safe arrival at Moreton Bay: Monday, June 20th Early this day the ship's company were employed in getting out the long- boat and pinnace, which they at length accomplished, and loaded them with a few casks of provisions and water, and all the people's clothes.

crew employed themselves in carrying the light goods to the island, until high-water, when the long-boat und pinnace were safely discharged.

The reef was covered with turtle, and the island abounded with birds, consisting, principally, of doves, magpies and sea fowl.

A party also walked across the reef, to a dry part of which a rope was passed from the wreck, and by this means a great deal of property was saved.

The main land of New South Wales was discernable from this island, on which the people remained till the 16th, when they were obliged to leave for want of water.

18th-About 12 o'clock p. m. the people went ashore on an island close to the main, where they fortunately found water, and having taken in a supply proceeded on their voyage.

The weather was in general fine from this time up to the 27th, when the shipwrecked mariners reached Moreton Bay in safety, where they were most kindly received, and every assistance afforded them by the Commandant, of whose gentlemanly and humane conduct the sailors are loud in praise.

In 1841, Blackwood was appointed to command the corvette HMS Fly in the first hydrographic survey commissioned by the Admiralty for exploring and charting the north-east Australian coast.

The Fly, fitted with costly instruments, and carrying two scientists, Joseph Jukes, geologist, and John MacGillivray, zoologist, sailed from Falmouth in April 1842 with the cutter Bramble, under the charge of Lieutenant Charles Bampfield Yule.

Jan 21 Captain Blackwood and Mr Evans being ashore to "take sights" for the chronometers, found on the island some traces of the wrecked crew.