After receiving further flight training in England, he was sent to North Africa with his navigator, Tom McGlade, to fly missions over the Mediterranean that included convoy escort, U-Boat search and strike, and general reconnaissance.

On one mission, they had just attacked a German U-Boat when an ME-210 fighter opened fire on them in a frontal assault that riddled the plane with bullets. The radio operator was killed outright, and Doc was hit in the legs by several bullets.

Since he was the only pilot on board, the crew tied his feet to the rudder pedals and he managed to fly the plane home and land safely. After his recovery, Doc returned to operations and completed a total of 82 missions. Doc served for five years in total with the RCAF, with extensive tours of North Africa, Sicily, and Italy.

Doc Seaman graduated from the University of Saskatchewan (U of S) with a B.S. degree in mechanical engineering. In later years he received two honorary Doctor of Laws degrees from U of S and the University of Calgary. He also received the Rotary International's Paul Harris Fellowship Award, and was appointed an Officer of the Order of Canada.

Some of his other achievements include a Governor General's appointment to the Royal Commission on Economic Union and Development Prospects for Canada, 1982-1985. He was awarded the Association of Professional Engineers Frank Spragins Award and the McGill University Management Achievement Award. In 1987, he was made a life member of the Associaton of Professional Engineers of Alberta. He was also inducted into the Saskatchewan Oil & Gas Industry Hall of Fame in 1989.

In 1994, he sponsored the D.K. Seaman Chair in Technical and Professional Communication at UofS. In 1997, he was inducted into the Canadian Oilmen's Hall of Fame. In 2001, he was made an honorary regent of the Athol Murray College of Notre Dame and received the Humanitarian Award. In 2004, he was inducted into the Calgary Business Hall of Fame.

Besides being a co-owner of the Calgary Flames, Mr. Seaman's hockey experience included the Notre Dame Hounds, Wilcox and the Moose Jaw Canucks. He was also an original Governor of the Hockey Canada Foundation.

On June 1, 2007, he was inducted into the Alberta Sports Hall of Fame together with his brother Byron and Harley Hotchkiss, as builders who brought the Flames from Atlanta to Calgary in 1980.