HMS Castor explained

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".

• was a 36-gun fifth rate that captured from the Dutch in 1781. One month later the French Frippone captured Castor off Cadiz.
• was a 32-gun fifth rate launched in 1785. She was briefly in French hands in 1794, but was recaptured. She was sold in 1819.
• was a 36-gun fifth rate launched in 1832. In 1860 she became a training ship, and was sold for breaking up in 1902.
• was a light cruiser launched in 1915. She was sold in 1936.