Pasted from usual source.
At the outbreak of the Second World War in 1939 a 40mm anti-aircraft gun was installed, the pier was constructed and the slipway strengthened.
An ammunition hoist was also installed and a tall gunnery control post was erected on the top of the Island.
Some concrete bunkers were built but the most interesting thing was the installation of a minefield control post, which, if there had been an invasion, would have detonated mines placed all over the Sound. By April of 1941 there were 490 troops stationed on this important point. Damage during the War was mainly from incendiaries but one person was injured and the canteen roof was damaged.
The War ended in 1945 and in 1956 the War Department announced that the Island was no longer needed for defence purposes. In the December the Ministry of Supply's workmen moved in to remove the six 12 pounders still operational on the Island as well as the fittings. They also demolished the gun emplacements. The War Department finally vacated the Island in 1963 so that an adventure centre could be started.
Between the main land at Western King's and the Island, at a depth of 108 feet, was a 3,000 foot long deltathene water pipe. It was laid by a cable-laying lighter on August 31st 1965, before which fresh water had to be taken across by boat and pumped ashore. On Sunday January 30th 1966 it was discovered that no water was getting to the Island and it was thought that the pipe had been fractured. [1]
Drake's Island was leased from the Crown by Plymouth City Council as a youth training centre. A covenant prohibited any commercial development on the Island. It was opened to the public in 1964, the year that mains water was finally laid on. Ten years later, as the Drake's Island Adventure Centre, custody passed to the Mayflower Centre Trust which was responsible for running the Mayflower Sports Centre in Central Park. In 1976 it was sold to the Council and later the remaining buildings became Scheduled Ancient Monuments.
A noteworthy event was the installation of a telephone, on May 1st 1987, using a cable attached to the mains water pipe. The telephone number was Plymouth 63393. The warden had previously used the Ministry of Defence system. Shortly afterwards, on March 31st 1989, the Mayflower Trust surrendered their lease and sold off the boats and sports equipment. Ownership reverted to the Crown.
In 1995 it was put up for sale through agents Messrs Knight, Frank and Rutley, and sold to Mr Dan McCauley, owner and Chairman of Plymouth Argyle Football Club, for a reported figure of £384,000. Various plans have been put forward to develop Drake's Island as a tourist centre but so far none have come to fruition.
just so the ship had enough clearance to manoeuvre around the bouys did give me a giggle tho 
