[2][1] As a child, Seligman attended Rokeby Preparatory School in Kingston upon Thames, London, but learned to sail while his family vacationed in Saint-Jacut-de-la-Mer, Brittany.

After failing natural science examinations at the University of Cambridge Seligman took work as a mess boy on a shipping freighter and began a career at sea.

[3] Seligman purchased a 250-ton French fishing Barquentine named Cap Pilar on the advice of Joseph Stenhouse, a commander in the Royal Navy and former participant in Ernest Shackleton's Discovery Expedition.

In 1941, Seligman and other reserve officers conducted a special operations mission to bring five ships from Russia to Syria through the German blockade at the Dardanelles.

[6] The vessels often operated under cover of darkness, landing or picking up commandos, rescuing partisans, and intercepting or raiding small German forces.