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A view from a helicopter while landing on Discover Enterprise drill ship during recovery operations in the Gulf of Mexico. - 

by Nancy Marshall Genzer

On top of the six-month moratorium already in place on deepwater drilling in the Gulf of Mexico, the Interior Department plans to order oil drillers in the Gulf's shallow waters to stop operations temporarily as well. But the suspension will likely only last a few weeks.

Officials seem to have decided that shallow water drilling is safer than drilling in deep waters. Is this true?

Most of the 3,500 rigs in the gulf are pumping in 1,000 feet of water or less. Fewer than 50 are in deep water. John Rynd drills in shallow water, sometimes just a couple hundred feet deep. He says it's a whole different world from BP's deepwater operations. For one thing, his blow-out preventers, designed to keep a well from exploding, sit on top of the water. "We walk down a flight of stairs and go to it, literally."

The crippled BP blowout preventer is down so deep it can only be reached by robots. Ditto for the blown-out well head. Divers can usually reach shallow wells. But some environmentalists say shallow wells are just as dangerous as deep ones. Especially for wildlife, says Kieran Suckling, executive director of the Center for Biological Diversity. "Wildlife can be even more affected by blowouts in shallow water because shallow water drilling tends to be much closer to shore."

Suckling says blowouts are more common in less than 500 feet of water. He points out that the biggest spill ever in the Gulf occurred at about 160 feet.