“Shadow Divers”

by Fran Withrow 11.2025

Deep wreck divers John Chatterton and Richie Kohler were rivals who disliked each other until, in 1991, a mysterious U-boat was discovered in the depths of the Atlantic Ocean off the coast of New Jersey. Over the next six years their rivalry disappeared as they became colleagues and then friends, working together to identify this German submarine which sank during World War II. How did it get there? Why were there no records of it being in that area? And how did it sink when no Allied forces reported its demise?

Robert Kurson’s “Shadow Divers” is a fascinating account of how deep sea divers Chatterton and Kohler eventually solved this baffling riddle. Their exhausting work required an incredible amount of time and money, and also took a host of other divers working with them. Sadly, not all of these divers survived.

Kurson not only writes about how the U-boat was finally identified but also takes the reader deep into the lives of deep sea divers. This type of diving is vastly different from the shallow scuba diving most people are familiar with. Deep sea diving entails massive amounts of preparation. Divers must plan for the side effects of intense underwater pressure, which can include mental and visual impairment as well as other frightening physical side effects. An added challenge in exploring an underwater vessel lying on the ocean floor is the potential to get lost inside a boat that may no longer be upright or intact, to get entangled in dangling wires and pipes, or to even be trapped if a wall or beam falls as they swim through.

This sounds so daunting one wonders why anyone risks exploring 230 feet below the surface, where this U-boat was found. Yet Kurson carefully fleshes out the lives of the divers, giving the reader a true understanding of the lure of the deep sea and the dedication required of those who love it. 

As the divers made repeated trips to the U-boat, gathering artifacts from the vessel and, on land, doing exhaustive research to uncover its identity, they began to feel deep empathy for those men who lost their lives and whose loved ones never knew what happened. Chatterton and Kohler made it a point to respect human remains, careful not to disturb bones and to only explore in areas without skeletal parts. 

Each artifact they hopefully lugged to the surface failed to have identification on it, frustrating their search for answers. The U-boat had been underwater for so long that most of these numbers had faded away.

Kurson’s writing about this adventure is intensely gripping, and I found myself reading far into the night. I held my breath as Chatterton, Kohler and other divers risked their lives in this watery grave.

Full of photographs of the divers, as well as a list of the U-boat crew members who lost their lives, this is an absorbing chronicle of two men who risked everything to identify a mysterious submarine and finally lay her seamen to rest.