ST. JOHN’S, N.L. — The wrecks of four iron ore carriers felled by German U-boats in 1942 have rested off Newfoundland’s Bell Island for decades.

Bell Island was one of the few places in North America to be attacked by German forces during the Second World War, and the sunken wrecks draw divers from around the world. But an unknown number of undetonated explosives, possibly up to 200, remain onboard, a possible danger.

On Monday, a retrieval mission is to begin from Conception Bay South, outside St. John’s, N.L.

Military divers will set out to retrieve the unexploded explosive ordnance from the rusting wrecks of the four iron ore carriers: the Lord Strathcona and Rose Castle from Canada, France’s PLM 27 and Britain’s Saganaga.

Diver Neil Burgess of Flatrock, N.L., said the ships, each about 120 metres long, have been taken over by strikingly gorgeous scenes of marine life, with plentiful, flower-like anemones and fish thriving in what are essentially battle sites — and, for three of the ships, grave sites.

After more than 50 dives, Burgess said visible evidence of the attacks has a sobering impact every time. He’s spotted the mangled places where a torpedo struck a ship, and personal effects strewn about from the dozens of men who lost their lives.

“It gives you pause when you see a shoe lying in the bathroom or somewhere, because you think, was one of these guys wearing this shoe when the ship went down?” Burgess said by phone on Thursday.

“The steel plates of the ship are bent like they were plasticine,” Burgess said. “You just thank your lucky stars that you weren’t there when the explosion happened.”

Burgess has also spotted artillery shells lying on the deck near the stern gun. The ships, carrying iron ore from Bell Island’s mines to steel mills in Sydney, N.S., to be made into war goods, had been outfitted with artillery guns to prepare for German attack.

Burgess, who’s also president of the Shipwreck Preservation Society of Newfoundland and Labrador, estimates there are about 50 shells on each wreck. He provided the team behind this week’s dives with old plans of the ships to help map out retrieval efforts.

The dives are scheduled to run from July 15 through July 24. The artillery will then be taken to a shooting range about 45 minutes west of St. John’s to be detonated.

The military ordered a survey of two of the shipwrecks in 2000 over fears that divers might accidentally trigger the leftover explosives.

At the mission’s end, the sites may be made safer for eager explorers who visit the wrecks each year.

Rick Stanley of Ocean Quest Adventures has spent the last two decades guiding tours of what he calls the “underwater museum” of the wrecks.

The tours are geared for experienced divers only, and draw guests from around the world.

Stanley said the connection to Canadian, British, French and German forces as well as Bell Island families who tended to the survivors draws visitors from diverse backgrounds.