The year is 1838, and after more than ten years in the planning, the famous United States Exploring Expedition is set to launch into uncharted waters from the coast of Virginia. A convoy of seven ships filled with astronomers, mapmakers, naturalists, and the sailors charged with getting them around the world, the "Ex. Ex." is finally underway, with much fanfare.

Aboard the convoy as ship's linguist is Wiki Coffin. Half New Zealand Maori and half American, Wiki speaks numerous languages and is expected to help the crew navigate the Pacific islands that are his native heritage. But just before departure Wiki, subject to the unfortunate bigotry of the time, is arrested for a vicious murder he didn't commit.

The convoy sails off, but just before the ships are out of reach Wiki is exonerated, set free to catch up with his ship and sail on. The catch: the local sheriff is convinced that the real murderer is aboard one of the seven ships of the expedition, and Wiki is deputized to identify the killer and bring him to justice.

Full of the evocative maritime detail and atmosphere that have won her numerous awards for her nonfiction, Joan Druett's A Watery Grave is the mystery debut of a masterful maritime writer.