Riptide is a novel by Douglas Preston and Lincoln Child, published in 1998 by Warner Books. The novel revolves around a plot to retrieve the buried treasure of nefarious pirate Red Ned Ockham. The treasure, which is estimated to be worth close to two billion dollars, reputedly includes "St. Michael's Sword", a weapon with the power to kill anyone who looks at it. The novel is pure fiction but is based in part on the legend of the Oak Island Money Pit.