As a result, more dumpsites likely exist, he conceded.

The environmental effect of chemical weapons dumpsites is unknown but potentially disastrous.

Ocean depth varies widely off the East Coast. As a rule, it gradually deepens to 600 feet before hitting the outer continental shelf, which drops into very deep water. The shelf's location can be as close as 60 miles, or as far as 200 miles, from shore.

"The perception at the time was the ocean is vast - it would absorb it," said Craig Williams, director of the Chemical Weapons Working Group in Kentucky, a grass-roots citizens group. "Certainly, it is insane in retrospect they would do it."

"It would be inevitable, I assume, all of this will be released into the ocean at some point or another," said Williams, who has fought Army plans to incinerate some of the 44 million pounds of chemical weapons the country still has stockpiled. "I don't think anyone knows for sure the true danger. It's just a matter of opinion. You can say, 'It's going to kill everyone,' or you can say, 'It's not a problem.' The truth is somewhere in between."

Based on the information available, the Army presumes that most of the weapons are in very deep water and are unlikely to jeopardize divers or commercial fishing operations that dredge the ocean bottom.

John Chatterton doesn't believe that.

"I don't think it all is where they say it is," said Chatterton, a 25-year veteran diver who searches for undiscovered shipwrecks as host of The History Channel's "Deep Sea Detectives." "I've found a lot of stuff where it's not supposed to be. Absolutely, positively, it is not a guarantee it is there (in deep water)."

Chemical weapons were dumped long before electronic navigation systems were invented. Their nautical locations are based on the words of ship captains, who surely wanted to ditch their cargo quickly and, Chatterton suspects, likely cut corners.

"The guys who were doing this were scared of this stuff. They were well motivated to get rid of this stuff as fast as they could," he said. "So they could take it all the way out there or else they could say, 'This is good enough,' and be back in port in three hours. I know what they did. It's mariner nature."

STATE OFFICIALS IN THE DARK

One of the first of the now-identified dump zones created at the end of World War II was also one of the largest. The Army dubbed it Disposal Site Baker.

The Army has only the vaguest idea where it is on the ocean floor - somewhere off the coast of Charleston, S.C., the most specific surviving records indicate.

"I have never had any information to suggest this was done," said Charles Farmer, a marine biologist who's worked for South Carolina's Department of Natural Resources for almost 40 years.

"I would say this is not well known to us at all. This is something that is new, at least to me. It's incredible some of the things we've managed to do."

The first documented dump near that state was in March 1946, when four railroad cars full of mustard gas bombs and mines were tossed over the side of the USS Diamond Head, an ammunition ship.

Several months later, an estimated 23 barges full of German-produced nerve gas bombs and U.S.-made Lewisite bombs were dumped in the same location. Lewisite is a blister agent akin to mustard gas. A single barge carried up to 350 tons.

"If we don't have any idea of depths of water or location, hell, they could be anywhere," Farmer said. "As we have more and more activity and more and more development off the coast, I hope this was buried in 6,000 feet of water ... or a lot of this stuff is going to come back to haunt us."

There's one indication that those weapons were dumped in relatively shallow water: Army records show many of those 23 slow-moving barges were unloaded in one-day, out-and-back operations.

The records leave no doubt that other chemical weapons were dumped close to shore: