HMS Diamond Rock: The Stone Frigate

South of Martinique, an island in the eastern Caribbean Sea, lies a small basalt island called Diamond Rock. With an imposing peak of 175 meters, the island is said to appear like a cut piece of the eponymous jewel during certain hours of the day. Despite being a mere rocky outcrop, Diamond Rock has quite a history.

HMS Diamond Rock from Martinique. Photo: Marc Bruxelle | Dreamstime.com

Located at the north end of the St. Lucia Straits, Diamond Rock occupied a strategic position. Possession of the rock allowed interdiction of navigation between Martinique and its southern neighbor, St Lucia. Yet, when Royal Navy Commodore Sir Samuel Hood arrived at Diamond Rock in 1803 with instruction to blockade the bays at Fort Royal and Saint Pierre, he found the rock surprisingly devoid of French presence. Sir Hood wasted no time and hoisted two 18-pounder cannons to the rock’s summit. Then, he hastily built fortifications and a garrison of two lieutenants and 120 men was established. Two additional 24-pounder guns were placed at the base of the rock, and another 24-pounder was placed in a cave halfway up the side of the rock. Furthermore, a six-gun sloop, designated HMS Fort Diamond was placed in service to support the fort at Diamond Rock.

Traditionally, naval bases in many Commonwealth countries, including the Royal Navy, are named after ships and thus carry the appropriate prefix (HMS in the Royal Navy, HMCS in Royal Canadian Navy, HMAS in Royal Australian Navy, INS in Indian Navy, and so on). The use of ship prefixes to denote naval installations has its roots in the age of sail, when navies used the hulks of old wooden ships moored in ports as floating barracks or classrooms to train sailors and officers. These hulks retained their HMS designations, and later, when these training facilities moved ashore to more permanent bases, the name moved with them. Another theory is that all sailors, by law, have to be on the payroll of a commissioned ship. So by naming naval bases as ships of the Royal Navy, service records could show personnel serving on a ship even though they are not at sea.

HMS Diamond Rock. Photo: Chromoprisme | Dreamstime.com

Going with this tradition, Hood officially commissioned the island as the sloop-of-war “HMS Diamond Rock”, under the command of Lieutenant James Wilkes Maurice. Other Royal Navy ships were required, when passing the island, to show due respect, with personnel on the upper deck standing at attention and facing the rock whilst the bridge saluted. HMS Diamond Rock made popular the term “stone frigate” which is another name for shore establishment.

The garrison on HMS Diamond Rock constituted the usual officers found on a British warship, including a surgeon, purser, and a junior lieutenant to command the small supply vessel. Maurice established a hospital, and food, gunpowder and ammunition were brought to the rock in boats from the islands of Centaur and Martinique, where it was purchased from sympathetic inhabitants. The principal weakness of the island was the lack of food and water, which had to be supplied by vessels foraging among the nearby islands. The sailors also kept goats, guinea hens and chickens on the island to supplement their uncertain food supply.

A cannon is hauled up to the summit of the rock suspended by a cable lashed to the base of Centaur's mainmast. Photo: National Maritime Museum/Wikimedia Commons

Life on Diamond Rock. Photo: National Maritime Museum/Wikimedia Commons

For 17 months, HMS Diamond Rock completely dominated the channel between it and the main island, firing towards French ships that attempted to wander too close to the rock and intercepted supplies destined for the French garrison. Because of its elevation, the guns on Diamond Rock had a long firing range, and this forced French vessels to give a wide berth to the rock. Between the guns of Diamond Rock and the currents and strong winds, it made approaching the harbor in Port Royal for the enemy ships nearly impossible.

The French decided to recapture Diamond Rock by creating a blockade and cutting off supplies to the island, thereby forcing the British to surrender. The plan, although a simple one, worked. After exchanging fire with the French for several days, ammunition and water began running low on the island, and Lieutenant James Wilkes Maurice was left with no option but to surrender to the French forces.

“Taking of the rock Le Diamant, near Martinique, 2 June 1805” by Auguste Étienne François Mayer. Photo: Wikimedia Commons

Maurice later wrote to Vice-Admiral Horatio Nelson:

It is with the greatest sorrow I have to inform you of the loss of the Diamond Rock, under my command, which was obliged to surrender on the 2d ist., after three days' attack from a squadron of two sail of the line, one frigate, one brig, a schooner, eleven gun-boats and, from the nearest calculation, 1500 troops. The want of ammunition and water was the sole occasion of its unfortunate loss.... [our losses were] only two killed and one wounded.

Maurice was tried for court martial for losing a ship—the island in this case—as Naval procedure of the time dictated, but was honorably acquitted for the loss.

The rock remained in French hands until the capture of Martinique by the British in 1809. The island was traded back to France at the conclusion of the Napoleonic Wars along with Martinique. It has remained a French possession since then, inaccessible, inhospitable and uninhabited.