HMS Engadine was a seaplane tender which served in the First World War. She was built as a Folkestone-Boulogne ferry by William Denny and Sons, launched on 23 September 1911 and named after the Engadine valley in Switzerland. She taken over by the Royal Navy in 1914 along with her sister ship HMS Riviera and modified by the construction of cranes and a hanger aft of the funnels so that she could carry four Short 184 seaplanes. There was no flight deck, the aircraft being lowered onto the sea for takeoff and recovered again from the sea after landing.

Her aircraft participated in the Cuxhaven Raid on Christmas Day 1914. At the Battle of Jutland in 1916, one of her seaplanes, piloted by Lieutenant Frederick S. Rutland with Assistant Paymaster G.S. Trewin as observer carried out an aerial reconnaissance of the German fleet. This was the first time that a heavier-than-air aircraft had carried out a reconnaissance of an enemy fleet in action. Later in the battle she rescued the crew of the crippled HMS Warrior before taking her in tow. Later in the war she served in the Mediterranean.

She was sold back to her original owners, the South Eastern and Chatham Railway Company in December 1919 and sunk by a mine with heavy loss of life in Manila Bay in December 1941 having been renamed Corregidor in 1933.

General Characteristics

• Displacement: 1676 tons
• Length: 316 ft (96 m)
• Beam: 14 ft (4.3 m)
• Draft: 16 ft (4.9 m)
• Complement: 250
• Armament: four 12 pdr (5.4 kg) and three seaplanes; two 3 pdr (1.4 kg), one 2 pdr (907 g) anti-aircraft guns and one seaplane added in 1915
• Armour: None
• Propulsion: steam turbine, 6,000 shp (4 MW), triple screw
• Speed: 21 knots (39 km/h) maximum