[sufue]

Raise the Titanic! is the fourth in the Dirk Pitt series by Clive Cussler. It has dropped to $1.99 at Kindle US.

link: https://www.amazon.com/dp/B0014E7IHO

Spoiler:

The President's secret task force has developed an unprecedented defensive weapon that relies on an extremely rare radioactive element--and Dirk Pitt has followed a twisted trail to a secret cache of the substance. Now, racing against brutal storms, Soviet spies, and a ticking clock, Pitt begins his most thrilling mission--to raise from its watery grave the shipwreck of the century...