He didn’t know it then, but the first time Tim Early ever went snorkeling he came within a few hundred yards of the shipwreck George F. Williams. It was August 1962, and Early was 15. “I swam right off where the Hammond Marina is now,” he says. “I was in the water a while, but I couldn’t see the Williams.”

Later one of those friends located the wreck 20 feet under the surface, but Early didn’t get out to it until the summer of 1983. Afterward he recorded the following: “Swimming straight out from shore, I knew I was bound to hit the target. I came upon a massive wooden ‘wall’ that I thought was a ship, but I couldn’t be sure. Then I began to swim along the side, and swim, and swim, and swim. It was gigantic, like being on an ocean liner in a dense fog. You know that you are on a ship, but you can only see a few feet of it at a time…. When I came to the end of the structure, there in front of me was a huge propeller. Each blade over six feet in length. It was not only a ship, it was one of the largest ships that I had ever been diving on.

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Al Konieczka, who worked for Encyclopaedia Britannica, read about the project in the local paper. He went to the National Archives office on South Pulaski, which he knew kept ship records. After searching through five musty boxes, he came upon drawings of the ship and an inspection report dated April 22, 1915. Records he found at the Institute for Great Lakes Research in Ohio filled in more details. “When I found out the name of that ship, I was like, ‘Hey man!’” Konieczka says. “I was wound up like a three-dollar watch–this was like a major accomplishment in my life.”

The George F. Williams, it turned out, had been built in Bay City, Michigan, in 1889 for a Cleveland company called Hawgood. It was a 280-foot cross between a sailing ship and a steamer–its hull was made of both wood and steel, and it had an engine in addition to four masts, though three of them were removed in 1893 to make the boat faster. It was one of the largest steamers on the Great Lakes, hauling coal with a crew of 20.

In February 1989 Early and Konieczka and another diver from the Hammond Shipwreck Project gave a lecture at Shedd Aquarium on what they’d discovered. “It definitely elevated interest,” says Early. But not from Hammond officials.

The Aquatic Resource Center was intended to “plug that gap.” In his spare time, Early gradually created an office and a classroom on the Milwaukee Clipper. He was still teaching diving and still going on scientific dives–he’d even helped set up an underwater preserve near Cozumel, Mexico. And he was publishing his own research–he’s written articles on controlling zebra mussels, on freshwater sponges, and on spawning salmon around wastewater-treatment plants in Indiana. “I know a lot about science,” he says, “but I’m a diver first.” Along the way he also learned to make underwater films.

Gentile shoots a lot of the videos, but that day the water was too murky. “I couldn’t see,” he said. “It was like diving in 2 percent–no, 1 percent–milk.”