After the 1815 Waterloo campaign, the regiment served in Halifax, Nova Scotia, where he died on 19 May 1823; his burial was led by General Sir James Kempt.

During the War of the Third Coalition, the first battalion of the 81st joined the British expeditionary force in Southern Italy; by now a captain, Waterhouse was wounded at the Battle of Maida in 1806.

[2] He was promoted major in November 1811, and after six years in Sicily, the 81st was assigned to the Catalonia expedition, a feint to help with the main Allied thrust in 1812.

[3] The battalion landed in Alicante in August 1812 and was involved in the failed seaborne attack on Dénia in October 1812.

[5] Waterhouse and the 81st remained on the east coast of Spain, taking part in the battles of Castalla Ordal, until the war ended in April 1814.