Commander Walker

At a time of peace during the Napoleonic wars, James Jenkins, a
Royal Navy captain, is found suspended under a dockyard pier in a cage.
He is rescued just before the tide drowns him. Jenkins, driven mad by
his ordeal, is confined to a private asylum by the Admiralty.
Admiral William Burns, suspecting that this attempt on Jenkins'
life is tied to the loss of his ship and its cargo of gold, tasks a
young commander, Albert Walker, to investigate the incident. This compelling
story of theft, murder and betrayal moves from London to the dockyards
to the high seas and the Caribbean as the commander and a trusted
friend, Lieutenant Samuel Mink, risk their lives to unravel the mystery.