Four ships of the Royal Navy have borne the name HMS Castor. Named after one of the Gemini twins in Greek mythology. Castor also means "he who excels".
HMS Castor was a 36-gun fifth rate frigate of the Royal Navy.
Castor was built at Chatham Dockyard and launched on 2 May 1832. She was one of a two ship class of frigates, built to an 1828 design by Sir Robert Seppings, and derived from the earlier Stag class. The Castor class had a further 13 inches (33 cm) of beam to mount the heavier ordnance. Castor cost a total of £38,292, to be fitted for sea.
Her first captain was Lord John Hay, and by September 1832 Castor was at Lisbon.
On 27 August 1834 she collided with the Revenue Cutter Cameleon off South Foreland, Dover, sinking Cameleon with the loss of most of its crew. This incident led to the Court Martial of officers and crew of HMS Castor on 6 September 1834 in Plymouth. The officers were acquitted but the lieutenant of the watch was dismissed from the service, it having been admitted and proven that a proper watch had not been kept.
She spent a period of time in the Mediterranean, before being decommissioned at Chatham in 1842. She spent periods in the East Indies and the Cape of Good Hope, with further periods laid up at Chatham. She came to the assistance of HM Troopship Birkenhead, when the Birkenhead was wrecked on 26 February 1852.
HMS Castor was a 32-gun Amazon-class fifth-rate frigate of the Royal Navy. She served during the French Revolutionary and Napoleonic Wars. The French briefly captured her during the Atlantic Campaign of May 1794 but she spent just 20 days in French hands as a British ship retook her before her prize crew could reach a French port. Castor eventually saw service in many of the theatres of the wars, spending time in the waters off the British Isles, in the Mediterranean and Atlantic, as well as the Caribbean.
Castor was ordered on 30 January 1782 and laid down in January the following year at the yards of the shipbuilder Joseph Graham, of Harwich. She was launched on 26 May 1785 and completed by July the following year. The ship was then laid up in ordinary at Chatham Dockyard.
Castor spent nearly five years in ordinary until the Spanish Armament of 1790 caused her to be fitted out at Chatham between June and August 1790 for the sum of £2,795. She commissioned in July that year under Captain John S. Smith, but the easing of international tensions caused Castor to be paid off later that year. The rising tensions with France immediately prior to the outbreak of the French Revolutionary Wars led the Admiralty to again prepare Castor for active service. She was fitted at Chatham between February and April 1793 for £4,066, recommissioning that February under Captain Thomas Troubridge.