The book is the exciting, true story of how divers John Chatterton and Richie Kohler struggled to identify a Nazi U-boat they help explore off the coast of New Jersey in the 1990s.
The author recounts how "We met at Chatterton's house, where he had parked his vintage Royal Enfield motorcycle next to Kohler's late model Harley."
The U-boat's grave lay barely within the reach of the scuba technology of the day. The wreck was badly damaged by the explosion that sank it, and was now a steel tube filled with jagged edges, piles of debris and wires reaching out to snag a diver. Time underwater had erased all the easy clues to its identity.
In finally proving this was the U-869, Chatterton and Kohler identified the final resting place of the submarine's crew.
Indirectly, they'd also bring recognition to the crews of two U.S. destroyer escorts who had been denied credit for the victory they'd scored in 1945. (This last wasn't verified until after "Shadow Divers" appeared — the full report appears on the U.S. Coast Guard website.)
After re-reading the book and enjoying it again, I wrote to Chatterton in 2012, to learn he had just moved to Florida and sold the Royal Enfield. He couldn't immediately lay his hands on any pictures of it.
"I do have a couple of pictures from when my wife and I were in the north of Thailand on 500cc Bullets with Himalayan Roadrunners," he wrote. "Actually, we got married on this trip, in Nan province.
"My wife and I made one trip from Kathmandu to Bhutan on Enfields, and another to the north of Thailand, where we got married. After the Bhutan trip, my wife bought me an Enfield I saw at the motorcycle show in New York City.
"Over the years, I have owned a Norton, a Triumph, a Kawasaki, a Yamaha, a Husqvarna, an Excelsior Henderson and several Harleys. I have a soft spot for the old British bikes."
Motorcycles must fill a relatively mild place in Chatterton's life, which has included service as a battlefield medic in Vietnam, hundreds of risky dives on other wrecks and cancer. He was at work under the Twin Towers when the airliners hit on Sept. 11, 2001.
"Shadow Divers" helped make Chatterton and Kohler public figures, and you may have seen them on the History Channel. You can read biographies of John Chatterton and Richie Kohler on their websites.
You can go along with Chatterton on a dive inside the U-boat on this YouTube video. I think you'll agree that his calm narration contrasts sharply with the clearly dangerous place he's exploring.