During his time at Cambridge University Seaman and a friend embarked on a three-day flight to South Africa, and he often cruised around Europe with his family.

In his early career Seaman won the Voiturette race of the Swiss Grand Prix event at Bremgarten on his first attempt, he went on to win it three times consecutively.

In 1935 Seaman enjoyed a fruitful year with ERA; he took pole position at the 1935 Dieppe Grand Prix, and won the junior category of the 1935 Coppa Acerbo.

Seaman competed in numerous hill climb events also, winning his class at Freiburg in 1936, impressively only a second behind the overall winner Hans Stuck in an Auto Union.

[citation needed] Eventually Mercedes team chief Alfred Neubauer invited him for a trial at the Nürburgring.

[citation needed] Seaman had his last outing in a Delage at the 1937 South African Grand Prix in East London from which he retired.

Outside of Europe, Seaman finished second to Bernd Rosemeyer at the American Automobile Association (AAA) sanctioned Vanderbilt Cup in Long Island, New York in the United States.

His friend and biographer, George Monkhouse, called Seaman's drive at the Swiss Grand Prix, in difficult wet conditions, the best of his career.

Leading the 1939 Belgian Grand Prix at Spa-Francorchamps during a wet race, Seaman crashed his car into a tree during lap 22.

Seaman had a difficult relationship with his mother Lillian, who did not support his decision to drive for a "foreign" team, especially one influenced by the Nazi Party.

Seaman divided most of his time between Worcestershire and London; spending a large amount of money on travel, he often enjoyed waterskiing.

In his autobiography, Mercedes teammate Hermann Lang described Seaman as "kind-hearted, cool and fair as a sportsman, just as I has always pictured Englishmen to be."

Seaman was privately complimentary of Hitler, and controversially gave a Nazi salute following his victory at the 1938 German Grand Prix.