with ammunition; unlike several other local forts, Parliament kept the castle operational, probably because of its ongoing role in defending Southampton Water. During the early 18th-century War of Spanish Succession it was equipped with up to 25 guns. The castle was modernised in the 1770s with a new parapet around the central keep, alterations to the gun embrasures around the outer wall and an expansion of the gatehouse with an additional set of rooms for the castle's captain. Reports in 1793, however, showed the castle's guns to be in a poor condition and complained that the fortification was under the command of an infirm, elderly master-gunner. Improvements were probably made at the start of the Revolutionary Wars that year, but in 1809 the geographer James Playfair described the castle as merely "a blockhouse with a garrison". In 1804, the castle was used to store munitions for the Sea Fencibles, fishing boats used as volunteer naval vessels to counter the threat of a French invasion. Seven guns were added to the castle's arsenal to protect against French attack. With the end of the Napoleonic Wars in 1815, the government coastguard took control of the castle, using it as a base to combat smuggling, taking advantage of the water behind the Calshot Spit as a good location to position their waiting interception vessels. By the middle of the century, two officers and forty-two men were stationed there. By the 1850s, there was renewed military interest in the site, and several proposals were made to redevelop it to mount as many 32 artillery guns; the plans were not taken forward, and it was noted that the presence of the 16th-century stone keep would create dangerous splinters in the event of any enemy artillery fire landing there. In 1887, the Castle Yacht Club was established just beside the castle along the spit. During the 1880s, concerns were raised that Southampton might be vulnerable to French attack using small ships armed with torpedoes. As a result, in 1894 the War Office took the castle back from the coastguard, building a boom across Southampton Water which was moved using three gunboats. The 16th-century castle was too small to host a gun battery to protect the boom, so a larger battery was built south of the old castle in 1895, armed with two and four 12-pounder (5.4 kg) quick-firing guns, supported by three searchlights mounted on the