The Socotra Sparrow

"After college, a tour of duty as a Royal Marine and an apprenticeship in a shipyard, Martin Sommerville goes to America to seek his fortune. The death of his sweetheart in an auto accident causes him to pack up and leave, seeking solace by drowning himself in work at several of the worlds famous shipyards.
Finding little comfort in this venture, Marty returns to his old haunts in Northern England.
A short time later, after moving to London, he meets a raven-haired beauty and her professor Father, who launch him on an exciting new career with many twists and turns.
He ends up as an undercover Agent disguised as a Lecturer in the professor’s marine engineering department.
Marty succumbs to the raven haired Cybil, as they develop into a crack undercover team, combating international terrorism. Their assignments thrust them into international intrigue in Great Britain, as well as Rome, and the French Riviera, where they become aligned with a wealthy German arms dealer and his Fiancé."