He took part in the defeat of a French squadron that had escaped Trafalgar at the Battle of Cape Ortegal, before serving as a captain of the fleet to Vice-Admiral Sir Charles Cotton.

Jersey had been fitted out as a hospital ship and assigned to Lord Howe's fleet for service off North America, and Halsted took his son with him as a midshipman.

[2] Lawrence served with his father for the next two years, and participated in a number of naval operations along the American coast before his transfer into Captain Richard Onslow's 64-gun HMS St Albans on 25 May 1778.

[2] Halsted's father died shortly after this, but Onslow took on the role of patron, and the two sailed to the West Indies with Commodore William Hotham's squadron to join Admiral Samuel Barrington.

[2] Halsted was rated master's mate during his time on the Bellona, and was present at the battle with the 54-gun Dutch ship Princess Caroline on 30 December 1780.

[2] Princess Caroline went out to the West Indies as a convoy escort, after which Halsted moved aboard the 74-gun HMS Canada under Captain the Honourable William Cornwallis.

[2] Halsted now entered a brief period of unemployment, which lasted until 18 November 1788 when he joined Cornwallis's new ship, the 64-gun HMS Crown, as his first-lieutenant and went with him to the East Indies.

[2][6] He remained in Crown for a brief period, before resuming his command of Atalanta in order to complete his survey work, also using the sloop HMS Swan for the purpose.

[7] The French Revolutionary Wars had by now broken out, and Halsted was quickly appointed as acting-captain of HMS Invincible under Rear-Admiral John MacBride.

[7][8] Halsted and Montagu took part in the naval manoeuvres of the Atlantic campaign of May 1794, but were not directly engaged at the Glorious First of June, where the British fleet under Lord Howe defeated the French under Villaret de Joyeuse.

[7] In May 1796 news reached Duncan that a Dutch squadron consisting of the 36-gun Argo and three brigs and a cutter had departed Flickerve, Norway, bound for the Texel.

[13] After this success Halsted was assigned to operate off the Irish coast, where he captured a number of privateers including the 4-gun Espiègle off Waterford on 18 May 1797, the 1-gun Brave off Cape Clear on 24 April 1798, the 20-gun Caroline on 31 May 1798, and the 20-gun Foudroyant on 23 January 1799.

[11] Phoenix went on to join the fleet under Rear-Admiral Sir Richard Bickerton, and Halsted was appointed to command a squadron blockading Elba.

[20] These four ships, under Rear-Admiral Pierre Dumanoir le Pelley, had escaped from the Franco-Spanish defeat at the Battle of Trafalgar on 21 October and were making their way to Rochefort.

[18] Halsted was promoted to rear-admiral on 31 July 1810, advanced to vice-admiral on 4 June 1814 and was nominated Knight Commander of the Order of the Bath on 2 January 1815.

[18][23][24] Flying his flag during his time on the station aboard HMS Isis, he became a popular commander, and was rewarded with the thanks of the Jamaican House of Assembly and a service of plate from the merchants of the island at the end of his tenure.

[18] Halsted was promoted to admiral of the blue on 22 July 1830 and advanced to a Knight Grand Cross of the Order of the Bath on 24 February 1837, at the same time as being placed on the 'good service pension' list.

[18] One of his sons, Edward Pellew Halsted, reached the rank of vice-admiral and wrote a number of books, including a study of screw-propelled naval ships entitled The Screw-Fleet of the Navy.

[25][26] His youngest son, Lieutenant Lawrence G Halsted, died at Bombay on 7 November 1847 while aboard his ship, the steam sloop HMS Spiteful.