It took about 10 days to survey the two sections, a monotonous process that Mullen says is like “mowing grass.” Horgan spent the next couple of weeks analyzing the data to put together a mosaic of the sea floor. While they found plenty of modern-day sailboats, dinghies and other debris, they did not find any “clear, stick-up-out-of-the-bottom shipwrecks,” Mullen says. “But we didn’t expect to.”

They did find a series of perfectly round sinkholes near Carysfort Reef, some about 50 feet across, depth so far unknown.

“We want to go back with the ROV and try to understand how they got there,” Mullen says. “We saw a couple of these type of sinkholes in the Mediterranean, but those were Ice Age type of things.”

They also found a number of reefs more than 100 feet deep that didn’t appear to be on any charts, Mullen says.

The mosaic also features some aberrations that appear worthy of further investigation. “One might be an old anchor that leads us somewhere,” he says.

The project got off the ground with funding from the Norman and Barbara Tomlinson Foundation of Miami. To survey all the Keys and investigate potential shipwrecks and unusual geological formations will take another $400,000, Koblick estimated.

“We’re doing it about as cheap as we can be doing this, and it still costs about $5,000 a day,” Mullen says.

Finding funding isn’t easy.

“It is a harder sell than treasure hunting,” Mullen says. “People have to have a more altruistic and historic bent than those investors looking for gold and all the romance that goes with that. But I think what we’re finding is exciting and well worth doing.”

The Marine Sanctuary’s Altmeier agrees.

“What they are doing is giving us a snapshot of our resources,” she says.

“That allows management to make good decisions. If we know about a unique resource that they come across … we can study it. Shipwrecks offer a unique opportunity to study time — a microcosm of a cultural event that took place.”