The British Admiralty placed orders for 20 s as part of the 1911-1912 shipbuilding programme for the Royal Navy, with 12 ships to the standard Admiralty design, and 8 more as builder's specials, built to the detailed designs of shipyards specialising in destroyer construction.
Porpoise was laid down at Thornycoft's Woolston shipyard on 14 March 1913 and launched on 21 July 1913 [REF].