For the fascinating new Diving for Treasure, veteran tec divers Vic Verlinden and Stefan Panis spent years diving and photographing treasure-laden wrecks.

What were your favorite dives of the wrecks you surveyed?

VV: Roompot, because I was the first to see the wreck after more than 150 years.

SP: For me, the wrecks on the Belgian and Dutch coast. That’s a relatively shallow part of the North Sea that allows for very long bottom times, so plenty of time to explore. Also, wrecks like the Christiaan Huygens or the Tubantia have a very rich and interesting history, so you never know what you might bump into.

diving for treasure book
Workers stack gold bars on the Egypt, part of a ­10-ton shipment that never reached ­Bombay (left); a bronze Buddha from gold-laden Dutch ­passenger liner Tubantia; a ginger pot found on Roompot; gin bottles from Tubantia.

Vic Verlinden and Stefan Panis

What was the toughest thing about this 20-year project?

diving for treasure book
Historical accounts link the true stories of these shipwrecks with newspaper reports from the time, attempts to salvage them and the artifacts that were discovered, creating an engrossing account of 17 vessels before and after their demise.

Vic Verlinden and Stefan Panis

VV: Some of the wrecks, such as ­passenger liner Drummond Castle off Brittany, are located in strong current and can be dived only a few times a year. Others such as Roompot in the North Sea ­are close to the coast with poor visibility. The ­photography was a big challenge.

SP: It’s a combination of factors, and time. To get the right visibility to get good shots, you sometimes have to organize several expeditions to a wreck, and to get the right historical information, it sometimes is a matter of years before finally finding the missing link.

Which of these wrecks is believed to have carried the biggest haul of treasure?

SP: The SS Laurentic, which went down off Ireland, had the biggest haul, a reported 43 tons of gold, with 20 bars still not found, and SS Egypt, off Brittany, with 2 percent of its 5 tons of gold still unaccounted for.