Professional scuba diver Ricky Yamamoto returns for a third adventure in Grogan’s Divemaster Ricky series (following Derelict), this time tasked by mysterious clients with collecting samples in the waters off southeast Asia. On the boat with her are old friend Captain Rich and the couple who hired them, Lonnie and Margo, lottery winners who are funding an environmental study. (Their boat’s name? Powerballer.) The expedition soon draws the scrutiny of pirates, the Thai navy, and the Myanmar authorities. As the situation sinks from bad to worse, Ricky finds her clients have been hiding things from her—and that she now must solve multiple mysteries and use her wits to save her life.

Ricky narrates, her observations powered with a lively humor, and Captain Rich is a great foil, with their ongoing love-hate relationship a highlight. The plot takes some time to really get moving, and then has so many twists (including a surprising personal connection) that readers will have to work some to keep up, but the snappy dialog, larger-than-life cast, and fascinating milieu keep the pages turning. “Give me warm, gin-clear water and colorful reefs,” Ricky declares, and her love for the sea sets her and the series apart, with this entry finding time for her thoughts on orca, threats to coral, and our changing oceans.

Also enlivening the book are some terrific diving scenes. Grogan delivers almost poetic descriptions of sea life and does a great job with the beauty of southeast Asia: a delta alive with tributaries and side-channels "was like a massive, shimmering fractal." Readers interested in diving technology will find much detail here, though Ricky & co. also find themselves in a number of action scenes, some of them on a Clive Cussler level of inventiveness. Through it all, Ricky shows a remarkable talent for both cool fatalism and self-preservation—she finds “a certain satisfaction” in kicking one adversary in the head—leaving readers to eagerly await what she'll get into next.

Takeaway: This scuba thriller series dives into danger with an agreeably light touch.

Great for fans of: Micki Browning’s Beached, Andrew Mayne’s The Girl Beneath the Sea.

Production grades
Cover: A
Design and typography: A
Illustrations: N/A
Editing: A-
Marketing copy: B+