On 23 January 1871, he was appointed to the command of the 1,031 ton paddle steamer cruiser HMS Basilisk,[2] in which he made hydrological surveys around eastern New Guinea.

[3] During the survey of the southern coast he discovered the harbour which he named Fairfax after his father.

The town established there, based on already existing native villages (principally Hanuabada) was named Port Moresby and is now the nation's capital.

[6][7] On 29 September 1876, Moresby took command of HMS Endymion, remaining in this position until 6 March 1878,[8] when he was appointed Captain-in-Charge of the Royal Naval Dockyard in the Imperial fortress colony of Bermuda.

[9] He was later promoted to rear admiral and died on 12 July 1922 in Fareham, Hampshire, England.