The Halifax Submarine Mine Field was established and operated between 1872 and 1907, one of the earliest built overseas. The location of the minefield appears to have be moved slightly North about 1900, the initial field one being overlooked by York Redoubt and the two 6-pdr Q.F. Batteries located there. In 1864 plans show a chain boom running from Pleasant Point Battery and Ives Point on McNab Island. There were initially two Submarine Mining Observation Posts, one at Ives Point and the other on the slope below York Redoubt. By 1900 the Observation Post at York Redoubt became redundant, although still shown on maps, with a new Submarine Mine Observation Post located adjacent to Fort Ogilvie on Pleasant Point.
The Submarine Mining Establishment was built on Georges Island. The remains of the Submarine Mining establishment in Halifax from this period are amongst the best preserved within what was the British Empire.