Battle of Grand Port - Operations Off Grand Port

Operations Off Grand Port

With Île Bourbon secured in July 1810, the British now occupied a large fortified island base within easy sailing distance of Isle de France. Even before Île Bourbon was completely in British hands, Rowley had detached HMS Sirius from the invasion squadron with orders to restore the blockade of Isle de France. Shortly afterwards, Sirius's captain Samuel Pym led his men in a raid on a coastal vessel moored off the southern side of the island. Two days after this successful operation, reinforcements arrived in the form of the frigates HMS Iphigenia, HMS Nereide and the small brig HMS Staunch. Nereide carried 100 specially selected soldiers from the 69th and 33rd Regiments and some artillerymen from the garrison at Madras, to be used in storming and garrisoning offshore islands, beginning with Île de la Passe off Grand Port, a well defended islet that protected a natural harbour on the southeastern shore. These fortified islands could be used to block entry to the ports of Isle de France and thus trap Hamelin's squadron.

Grand Port was an easily defensible natural harbour because the bay was protected from the open sea by a large coral reef through which a complicated channel meandered, known only to experienced local pilots. Île de la Passe was vitally important in the control of Grand Port because it featured a heavy battery that covered the entrance to the channel, thus controlling the passage to the sheltered inner lagoon. The British planned to use the troops on Nereide, under her captain Nesbit Willoughby, to storm Île de la Passe and capture the battery. Willoughby would then use a local man serving on his ship named John Johnson (known in some texts as "the black pilot"), to steer through the channel and land troops near the town, distributing leaflets promising freedom and prosperity under British rule in an attempt to corrode the morale of the defenders.

The first attack on Île de la Passe was launched on the evening of 10 August, with Staunch towing boats carrying over 400 soldiers, Royal Marines and volunteer sailors to the island under cover of darkness, guided by Nereide's pilot. During the night however, the pilot became lost and the boats were scattered in high winds and had not reassembled by dawn. To distract French attention from the drifting boats, Pym directed Captain Henry Lambert in Iphigenia to sail conspicuously off Port Napoleon, where the main body of the French squadron, led by Hamelin in Vénus, was based. Pym joined Lambert later in the day and the frigates subsequently returned to the waters of Grand Port by different routes, confusing French observers from the shore as to British intentions. By 13 August, the boats originally intended for the attack had still not been assembled and Pym decided that he could not risk waiting any longer without the French launching a counterattack. Launching his own boats at 20:00 (local time), guided by the pilot and commanded by Pym's second in command, Lieutenant Norman, Pym's marines and sailors landed on the island in darkness under heavy fire from the defenders. Norman was killed in the initial exchange of fire, but his deputy Lieutenant Watling seized the island by storming the fortifications surrounding the battery. Seven British personnel were killed and 18 wounded in the battle, in which the storming party managed to seize intact French naval code books and took 80 prisoners. Willoughby was furious that Pym had assumed command of the operation without his permission and the officers exchanged angry letters, part of an ongoing disagreement between them that engendered mutual distrust.

With Île de la Passe secure, Pym gave command of the blockade of Grand Port to Willoughby and returned to his station off Port Napoleon with Iphigenia. Willoughby used his independent position to raid the coastline, landing at Pointe du Diable on 17 August on the northern edge of Grand Port with 170 men and storming the fort there, destroying ten cannons and capturing another. Marching south towards the town of Grand Port itself, Willoughby's men fought off French counterattacks and distributed propaganda pamphlets at the farms and villages they passed. Willoughby re-embarked his troops in the evening but landed again the following day at Grande Rivière to observe the effects of his efforts. Burning a signal station, Willoughby advanced inland, but was checked by the arrival of 800 French reinforcements from Port Napoleon and returned to HMS Nereide. The brief expedition cost the British two men wounded and one missing, to French casualties of at least ten killed or wounded. Willoughby followed the attack on Grande Rivière with unopposed minor landings on 19 and 20 August.