From the back cover...
Tasman Sea, 1856. A British clipper ship bound for Australia's penal colony is crushed in a raging typhoon. A few pitiful survivors wash up on a deserted island. Among these are Betsy Fletcher and Jess Dorsett, who discover an immense supply of exquisite diamonds..
Seymour Island, Antarctica 2000. Dirk Pitt rescues Maeve Fletcher, a descendant of Betsy and Jess, after an unknown cataclysm kills thousands of marine animals plus nearly two hindered people aboard a cruise ship. Pitt traces the carnage to the global diamond operations of Maeve's father Arthur Dorsett, and her callous sisters.
I've only read a few Cussler thrillers but so far they are exciting satisfying adventures, so I see no reason not to continue. I haven't read them in order and don't feel I have missed anything which is unusual for me because I prefer to go in order.