A tight, vivid sea-melodrama about an American whaling captain's private, pre-Pearl Harbor war against Nazi U-boats. Captain Robert Gerrard's pregnant wife died when a U-boat sank the unarmed liner Athenia--so when Gerrard happens upon an unaware Nazi sub (while hunting whales off So. Africa), he rams it, only to discover that his insurance company has gone out of business and cannot cover the damage. But meanwhile the British are desperate to transfer their South African gold reserves to the US (to buy ships). And Englishman Ralph Holden devises a scheme for buying Gerrard's whaler, Tulsar, through the defunct insurance company and using it to ship the gold; as a cover the Tulsar will take 20 passengers to the US while its hold is refitted to carry the gold bullion (over 200 tons). Opposing this mission: the German admiralty's Canaris (tipped off by traitor Holden via Kramer, a Nazi-sympathizing South African)--who dispatches a U-boat, captained by Gerrard's old arch-enemy Kurt Milland, to intercept the Tulsar and hijack the gold. The Tulsar sails; Kramer is on board, a stowaway sending radio signals to Milland; and the story turns into a battle of wits between Gerrard and Milland as both their ships sustain damages and become more enfeebled. Finally, when Canaris sends his huge ship the Bismarck to the sub's aid, the ship is sucked into a British trap and sunk. (The Tulsar was, in fact, carrying lead, not gold, and Holden was not a traitor but part of a plot to sink the Bismarck). Not quite convincing as speculative history--but a sharp, neat blend of action and suspense.