Riptide by Douglas Preston and Lincoln Child

For centuries, treasure hunters have sought the lost horde of the notorious English pirate Edward Ockham. Clues led to the mysterious Water Pit on Ragged Island, Maine-but a curse left behind by the long-dead Ockham seems to be working. Every expedition has failed; the treasure seekers died in gruesome fashions. Now a new expedition has been mounted, using state-of-the-art computer technology and backed by tens of millions of dollars. It will all be worth it, if the treasure estimated to be worth $2 billion can be found. But modern technology, no matter how expensive, may not be enough to overcome the deadly secrets of the Water Pit.