He followed the Spanish for several days, proceeding to give the earliest intelligence dispatches to Admiral Sir George Rodney, whom he found at anchor at Barbados.

[2] On 25 February 1781, whilst cruising twenty leagues off Cape Finisterre, he captured the Spanish 28-gun frigate Graña, under Don Nicolás de Medina.

He soon transferred his flag to the 74-gun HMS Cumberland and sailed from Portsmouth in March 1795, through the strait of Gibraltar to reinforce the Mediterranean Fleet under Admiral Sir William Hotham off the east coast of Menorca.

He was given command of a detached squadron in 1796 and sailed to Gibraltar with seven ships to watch the French fleet at anchor at Cadiz under Admiral Joseph de Richery.

At 11 pm, helped by an easterly breeze, the Spanish bore up and captured the merchant brig and one of the transports, but Mann and his seven ships of the line managed to escape into Rosia Bay, near the mole of Gibraltar.

[5][6] Mann then held a conference with his captains, and decided not to return to the Mediterranean, but instead to sail north with a convoy, and then cruise off Cape Finisterre for a time.

Mann had no authority to make this decision, and it infuriated Jervis, who accused him of jeopardising the British strategy and forcing a temporarily withdrawal from the Mediterranean.

Starved of supplies, and unable to re-join Jervis and the Mediterranean Fleet, and with promises of support from home unfulfilled, he returned to England.

His actions were misunderstood by Nelson (who otherwise regarded him highly), and seized upon by Jervis (forced to leave the Mediterranean because of a lack of a suitable base) eager for a scapegoat.