right|thumb|A map of Whale Island from 1945
right|thumb|A map of Whale Island from 1833
Whale Island is a small island in Portsmouth Harbour, close by Portsea Island. It is home to HMS Excellent, the oldest shore training establishment within the Royal Navy, and the location of the Navy Command Headquarters. The island is linked to Portsea Island and thence to the mainland by road bridges.
Early history
Ordnance Survey maps of Portsmouth Harbour from 1862 show Whale Island as a narrow strip: its east-to-west dimensions were similar to present times, but north to south it measured only tens of yards. To its northwest was Little Whale Island. Modern Whale Island is predominantly reclaimed land, using the deposits dredged from Portsmouth harbour during the 19th century, increasing the land area by about 125%. It was constructed with the help of the many prisoners taken in the Napoleonic Wars.
Expansion
During 1867 a viaduct was constructed from the north wall of the dockyard to the south-east corner of Big Whale Island which allowed spoil to be moved from dredging the docks (part of the expansion of HMNB Portsmouth), reclaiming the land between Big Whale Island and Little Whale Island, forming the basis of the island as it is today.
Before World War II Whale Island was home to a zoo which gave a home to several animals presented to British representatives by friendly countries. and prospective visitors are advised to contact the base.