The old site of HMAS Platypus in Sydney Harbour was handed over in 2005 to the Sydney Harbour Federation Trust, who will manage the conservation of its heritage for the general public as they are also doing for seven other former Defence sites around Sydney Harbour. On 18 August 2007, the fortieth anniversary of the commissioning of HMAS PLATYPUS and the arrival of the HMAS OXLEY to form the Australian Submarine Squadron, Vice Admiral Ian MacDougall AC AFSM RAN (rtd) spoke of the history of Australian submarines at the base and brought back memories for the assembled representatives of government and the Trust, members of Submarines Association Australia and other members of the submarine community and Australian Naval Cadets. Admiral MacDougall's speech has been entitled the 'Platypus Address', intended to be delivered each year by eminent submariners invited from Australia and overseas, to commemorate the commissioning of HMAS Platypus to support the modern Australian submarine squadron. This inaugural address is reproduced here by kind permission.