Excerpt from Pirate Hunters by Robert Kurson, plus links to reviews, author biography & more

So, he offered them a deal.

He would give them 20 percent of the Golden Fleece if they found the pirate wreck for him. There might be gold, silver, and jewels aboard. There might be swords, muskets, pirate beads, peg legs, and daggers. Even skeletons. Or there might be nothing at all. In any case, Bowden wanted something bigger than treasure. He wanted Bannister, the greatest pirate of them all.

Bowden didn't require an answer on the spot. He knew Chatterton and Mattera were about to embark on their own journey. He admired their guts and vision—it reminded him of when he'd thrown over his own safe American life to seek his Caribbean fortune. But Bannister's Golden Fleece was once in a lifetime. Think it over, he told them, and give me your answer soon.

Pulling out of Bowden's driveway, the two partners said almost nothing, but each was thinking the same. Between them, they'd dived the most famous and fascinating shipwrecks in the world—Titanic, Andrea Doria, Lusitania, a mystery German U-boat, Britannic, Arizona—but neither could imagine anything cooler or rarer than a Golden Age pirate ship, especially one captained by a gentleman sailor turned rogue who had defeated the Royal Navy in battle. Every diver, at some deep level in his soul, dreamed of discovering a pirate ship. Yet, it never seemed to happen to anyone. Ever. Now, Chatterton and Mattera were being given a chance to find one that sounded as thrilling as any history had known.

Yet, both men knew they could never accept Bowden's offer.

They had trained for two years to find treasure, spent hundreds of thousands of dollars on boats and equipment, pledged their lives' savings to the cause. They'd put together a crew, researched at archives in Spain, consulted legends and gurus, nearly got into gunfights in wild but beautiful places, survived an attack by shadowy rivals. It all had led them to a target few others knew about, a galleon called the San Bartolomé, sunk in a hurricane in 1556 on the Dominican south coast, and still filled with mountains of treasure. They knew she was there. They'd come too far to turn their backs on her now.

In another era, the two partners might have delayed their search for this treasure ship, but time was running out for treasure hunters now. Governments and archaeologists had pressured many of the countries richest in treasure wrecks—Jamaica, Mexico, Cuba, the Bahamas, Bermuda—to outlaw private salvage. Just a few years earlier, the United Nations Educational, Scientific and Cultural Organization (UNESCO) established an international treaty effectively holding that shipwrecks more than one hundred years old belonged to the nations that lost them, not to the person who found them. Already, several countries had adopted the treaty. The Dominican Republic had managed to hold out thus far, but it was just a matter of time before it signed on, too. In 2008, if a person intended to hunt treasure in that country, that person had to go now.

Time was running out on the divers, too. Chatterton was fifty-seven, Mattera forty-six. Both were much older than most participants in deepwater-wreck diving, a sport that pushed the body to its limits and could paralyze or kill a person for the slightest mistake. Most got out of the game by forty; those who stayed longer often just dipped their toes on the weekends. But galleon hunting was no part-time job. To do it, Chatterton and Mattera had to be ready to spend full days in the water, perhaps for weeks or even months on end. They couldn't afford to grow older by searching for a pirate ship that very well might not be there.

And there was no guarantee they could afford a pirate ship search, in any case. Both men had begun life as blue-collar workers; neither was independently wealthy. Together, they'd invested nearly a million dollars to hunt for a galleon. If they detoured now for a pirate ship, they risked expending what remained of their funds to find a wreck that might have no treasure at all.

Excerpted from Pirate Hunters by Robert Kurson. Copyright © 2015 by Robert Kurson. Excerpted by permission of Random House. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.