The Colonist was a wooden schooner of about 105 tons, roughly 23–24 m (76–78 ft) long with a 6 m beam, built in 1861. She had an eventful career: on 22 May 1870 she struck Elizabeth Reef, about 550 km off the NSW coast, but was refloated and brought back to Sydney in March 1871. Her end came in Sydney Harbour on 1 March 1890, when she sank after a collision with the steamer Adelaide.

Because she lay in the harbour's main shipping channel, the wreck was blown apart with dynamite in April 1890 to clear the fairway, and for more than a century her exact position was lost. Maritime archaeologists relocated the site on 13 May 2013 in about 20 m between Bradleys Head and Garden Island. What remains is the outline of the hull traced by the Muntz metal sheathing that once protected the timber below the waterline, and a pile of basalt – part of her final cargo.

It is protected under the Underwater Cultural Heritage Act 2018. Divers interested in Sydney Harbour wrecks can instead visit sites such as the Centennial in Taylors Bay, which is diveable with care. The Colonist's value is historical: a well-documented example of a small colonial trading schooner whose loss and deliberate demolition reflect the harbour's working past.

The wreck lies in Sydney Harbour's main shipping channel between Bradleys Head and Garden Island in about 20 m, relocated by maritime archaeologists in May 2013. It is not a recreational dive site: diving in the channel requires Port Authority of NSW approval and a vessel exclusion arrangement, and the area carries ferries, cruise ships and naval traffic. The nearest launching points would be Rose Bay or Rushcutters Bay, but any visit should be organised through Heritage NSW or the Port Authority rather than attempted independently.

Inside Sydney Harbour and sheltered from ocean swell, but visibility in the main channel is often poor, especially after rain or on the ebb, and tidal flow runs along the channel. The overriding constraint is shipping: ferries, cruise ships and naval vessels use this stretch around the clock, so diving is only possible under a formal arrangement with the Port Authority during a controlled window. Wind is a secondary issue, although strong north-easterlies raise a chop across the open harbour.

Not a recreational dive. Any archaeological or authorised dive would descend a shot line to the ballast pile and hull outline in about 20 m during an agreed shipping window, with surface support and a vessel exclusion zone.

Archaeological site; no recreational access without approval.

No operator – archaeological access only (Heritage NSW / Port Authority of NSW approval).