Navy Captain.

Promoted by his father to lieutenant, 1771; commander of sloop Tamar, 1773; commander of mail ship Mercury, returned to England to announce British capture of Rhode Island, 1776; the Mercury was wrecked in the Hudson river on hitting a ship hull that had been sunk underwater as a barrier by the colonists, 1778; court-martialed for the loss of the Mercury but aquitted, 1778; commanded the Medea in the North Sea, 1778-1780; command of the Juno, 1780; at Bombay, India, 1782; at action off Cuddalore, 1783; returned to England, 1785; 12-month leave to France, 1786; command of the Montagu (74 guns) as part of the Grand Fleet under Howe, 1793-1794; killed in battle of Ushant, 1794.

See napoleon-series.simplenet.com/battles/otherbattles.html (will have to search for Ushant).
www3.sympatico.ca/dis.general/queen.htm (Search for Montagu).
www.stvincent.ac.uk/WfS/Tourism/Portsmouth/HistShips/victory.html

Sources:
[DNB].

http://www.montaguemillennium.com/familyresearch/h_1794_james.htm