Blue Water by Leonora Nattrass is the first-person account of an intriguing trip across the Atlantic on the mail ship, Tankerville, in the company of some scheming passengers such as two fugitive French aristocrats, an American cotton plantation owner, an Irish performer who may or may not be a spy, and a maybe-freed slave.

The story is written as the personal report of a disgraced ex-clerk from Britain’s Foreign Office, Mr Laurance Jago. Blue Water is set entirely aboard the mail ship Tankerville as it sails from Britain down the Spanish coast to Northern Africa, west to the Caribbean and then north to Philadelphia. Heading across the Atlantic, the captain discovers a shortage of fresh water and returns to a Portuguese port where they are harassed by a French war ship. Readers of Patrick O’Brian’s Master & Commander series will be in their element as they read of the ongoing harassment and eventual encounter with the French war ship.

Mr Laurence Jago is in fact not a former Foreign Office clerk. His secret mission is to help a civil servant charged with the safe delivery of a most-important treaty to the US Congress. The treaty will stop the Americans joining the French in their war against Britain. The civil servant who hid the Treaty for safekeeping is ‘accidentally’ killed and so Mr Jago now faces the task of finding the Treaty’s hiding place. He realizes that several of the other passengers also want to find the treaty and suspects both the captain, some of the officers and most of the crew of also seeking the treaty for financial reward. A second death makes Mr Jago realize he must find the Treaty quickly, if no one else already has, and, to add to the tension, that he may be the killer’s next target.

I enjoyed this book and recommend it to readers of mystery and suspense and to the niche group of readers of historical maritime novels. The plot is well-paced, but don’t expect thrilling naval chases and battles. This is an interesting and extended interaction between richly-crafted and intriguing characters. The language is appropriate for the era and we are treated to a descriptive glimpse into ship life to such an extent that the plot and the finale were less significant to my enjoyment of the book than the whole story which I savoured rather than devoured.