Jack Higgins: Thunder Point (UK 1998)

From the Publisher:
A u-boat, sunk in the deepest waters of the Caribbean, has remained hidden for almost 50 years. But the discovery of the secrets it holds could bring down the British Government. The race to find the sealed container, to use it or destroy it, is fiercely contested by many interested parties.

Jack Higgins: Thunder Point. Berkley Publishing Group, ISBN: 0140280316 (November, 1998), 361 p., pound;6.99.

Jack Higgins: Thunder Point (USA 1994)

From the Publisher:
In 1992, the wreck of Nazi leader Martin Bormann's submarine is discovered in the Caribbean--along with a secret list of Nazi sympathizers. The names include high-level citizens from the U.S. and Great Britain, but the evidence is at the bottom of the sea. The British government turns to its greatest enemy for help--infamous terrorist Sean Dillon.

Jack Higgins: Thunder Point. Berkley Publishing Group, ISBN: 0425143570 (September, 1994), 368 p., $7.99.