On account of World War I, Beament interrupted his studies to join the Royal Canadian Navy Volunteer Reserve (RCNVR).

In 1935, Beament won the Jessie Dow Prize at the Montreal Museum of Fine Art Spring Show.

At the outbreak of WWII, Beament entered full-time service with the RCNVR, as a commander of minesweepers and escort vessels on North Atlantic patrols (1939-1943).

He rose in rank to Commander in 1943, then as official Canadian war artist, painted scenes at sea till 1947.

He held two solo shows at Laing Galleries, Toronto in 1948 and 1949 and painted a wide variety of subjects while travelling extensively.

[5] One Inuit figure by Beament can be seen on a 1955 ten cent stamp that he designed for the Canadian Postal Service (now Canada Post).