Greek ship Hydra
Five ships of the Hellenic Navy have borne the name Hydra or Ydra (Ύδρα), named after the island of Hydra, which played a major role in the Greek War of Independence: Hydra (1827–1831), a 26-gun sail corvette captured from the Egyptian fleet in 1827, destroyed in 1831 at Poros during a rebellion against Governor Ioannis Kapodistrias Hydra, a 433-ton steam gunboat built at the Black Wall Shipyard in England in 1891.