An important piece of America's history lies deep beneath the Gulf of Mexico waves. Dozens of ships setting out to provide England with petroleum during World War II now litter the sea floor, targets of German U-boat bombings.
In fact, the Gulf holds the greatest concentration of Allied vessels lost to German U-boats anywhere in the world, with 56 ships sunk here in 1942 and early 1943.
But because many of them are so far below the surface, no research has been attempted - until now. In what is considered the most comprehensive deep-water shipwreck study, scientists set out this week to learn more about seven of the vessels, including one German U-boat, the U-166, which sunk the Robert E. Lee only to meet a similar fate itself.
But the research isn't strictly historical. Just as important to scientists is the biological aspect of the sunken structures. Lying on the muddy Gulf floor for more than six decades, these ships have become artificial habitats for plants and animals. Whether these man-made reefs in the dark depths are as effective as those in shallower waters will be a major focus of the study.
"In shallow water, artificial reefs have definite benefits. They become just an oasis of life," says Herb Leedy, a biologist with the US Minerals Management Service (MMS), which handles the nation's offshore mineral resources. "But we don't know much about their benefits below where the light reaches."
So the MMS has teamed up with the National Oceanic and Atmospheric Administration for this 18-day, $1.2 million expedition. The idea is to use these shipwrecks to determine if their "rigs-to-reefs" program can be expanded to deeper water.
Since the early 1980s, the federal government has worked with coastal states and oil companies to convert platforms into artificial reefs once the rigs are removed, either by being towed to a new site or toppled in place.
So far, only Texas, Louisiana, Mississippi, and Alabama have enacted formal rigs-to-reefs programs. The Gulf of Mexico, with more than 200 in its shallower waters, hosts the vast majority of the platforms in the program. Florida has towed some off their coast, but not since 1993. And the California legislature has been debating the idea for its past several sessions.
Government officials are hoping this new research will encourage more coastal states to adopt the rigs-to-reefs program - and perhaps, says Dr. Leedy, it will lead to the discovery of new species.
The seven ships in the study were chosen because they provide an ideal laboratory. They've all spent about the same amount of time underwater and are fairly close together. They also reflect a range of depths, from 280 feet to 6,500 feet, and were carrying a variety of cargoes, which may have had an effect on the steel hulls and sea life they've attracted.
"It's a great opportunity to look at how each of these structures has been colonized over essentially the same time period," says Jack Irion, a marine archeologist with MMS. "But we are also interested in how these ships have deteriorated over time."
Part of Dr. Irion's job will be to help photograph and document each vessel the team encounters for future study and possible nomination to the National Register of Historic Places. They will explore using a remotely operated vehicle.
During the months after the US entered World War II, German U-boats secretly patrolled US waters - targeting oil tankers and ships ferrying food, ammunition, and other supplies to the Allies overseas. Originally, Adm. Karl Doenitz, commander of the German submarine fleet, wanted to plant a dozen U-boats off the Atlantic coast and stop the ship traffic. But Hitler allowed only six, believing that his enemies would attack from the North Sea. In the first months of the offensive, U-boat captains sank almost 400 vessels in US waters and killed more than 5,000 people.
"The US was virtually caught unawares," says Irion. "Up to that point, ships were venturing out without escorts. There were no blackouts on board. It was like shooting ducks in a barrel."
Eventually, the US caught on and began sending ships out in conveys - so the Germans moved their operation to the Caribbean and Gulf of Mexico, where ships were still being sent out unguarded. When shipping here was crippled, the US built the first interstate pipelines from East Texas to New Jersey to help solve the problem.
"Many people don't realize how very close we came to losing World War II right in the opening salvos," says Irion. If all 12 U-boats had been allowed to come, "the whole course of history might have been different."