Britannia was a 301 burthen ton full-rigged whaler built in 1783 in Bridport, England, and owned by the whaling firm Samuel Enderby & Sons.

Under the command of Thomas Melvill (not Melville), Britannia was one of 11 ships that departed from the United Kingdom in early 1791 as part of the Third Fleet, bound for the Sydney penal settlement.

Britannia left on 7 January 1792, intending to cruise for three months, and then either sail back to Port Jackson, or for England, depending on her fortunes.

[10] Britannia, under command of Robert Turnbull, departed England in early 1798 and arrived in Port Jackson on 18 July 1798.

She spent a little over two months at sea, perhaps some 30 leagues off shore, and returned on 29 December with 60 tons of spermaceti oil.

[14] While at Port Jackson Captain Turnbull was one of three South Sea whaling masters interviewed by Governor King about the best route to Australia and the relative merits of the whale fishery offshore compared with that off the west coast of South America.

She returned to Port Jackson 12 May 1802, and reported to Governor King at New South Wales that she had gathered 1300 barrels of oil.

Britannia sailed again on 17 September 1804, for the Pacific Ocean, with Nathaniel Goodspeed (or Godspied, or Godsped), master.

Two were rescued the next day while the other three found another boat, put water and biscuits on board, and launched it.