NINETY miles south of New Orleans, a supply boat pulls alongside a jackup rig, the Glomar High Island IV. A crane operator on the rig lowers a rope basket to the wave-tossed boat. As waiting roughnecks grab hold, the operator hoists them several hundred feet through a ripping March wind and lands the fresh crew members safely on the rig's deck.
Standing nearby is Russell Luigs, chairman of Global Marine Inc., the company that owns the High Island IV. Mr. Luigs explains to visiting reporters that the crew is drilling in search of natural gas below a long-depleted oil field. As he strides around the massive metal machinery, Luigs points out that the advanced-design rig can operate with "zero discharge" into the waters below.
And he means zero. At a drill site in fish-rich Mobile Bay off Alabama, Luigs found "one-half tablespoon rainwater" entered in the rig's Inadvertent Discharge Log. On another occasion, a roughneck who tossed a wadded-up package of cigarettes over the side was instantly fired.
And yet - despite rigid procedures and new technology that enable the offshore industry to tread lightly on the subsea environment; despite the fact that drilling and production rank far below municipal waste, urban runoff, natural seeps, and air pollution as sources of oil in the ocean; despite the employment, trade balance, and national security benefits to the United States of producing its own energy - the political distance between the oil industry's drill bits and the nation's remaining offshore pe troleum wealth continues to lengthen. Legislation now before Congress would postpone exploring much of the outer continental shelf (OCS) until after the year 2000.
The pending energy bill might even require taxpayers to buy back leases for which oil companies already paid $900 million. The Natural Resources Defense Council and other environmental lobbying groups write of those lease sites in superlative terms. Bristol Bay, Alaska, is "the single most important region of the entire OCS for marine mammals, endangered species, and fishery resources." The Florida Keys and Everglades are "unique and extra- ordinarily sensitive." Offshore North Carolina is "the most prod uctive benthic environment ever found off the East Coast."
So when do we drill? The oil industry wants to know. Its OCS drilling and production activities have spilled scarcely a barrel of oil since the 1969 blowout off Santa Barbara, Calif., according to the Minerals Management Service (MMS), a federal agency in charge of offshore oil leasing.
In that accident, the operators quickly killed the well. But reservoir pressure forced up to 70,000 barrels of oil around the bottom of the pipe and up through cracks in the ocean floor - the first and only time that has happened. A simple change in procedure - cementing the well's steel casing into place more often during drilling - has made a recurrence impossible, the industry insists.
Roger McManus, a biologist who heads the Center for Marine Conservation, acknowledges that the industry's pride in its offshore environmental record is justified.
"Yes, the risk is not huge," Mr. McManus says, "but is it a risk you want to take?" The oil industry, he adds, "has never learned to recognize and respect other people's values in the offshore environment. The industry has largely insisted that they can drill anywhere they want to, and repeatedly - through Congress and through administrative action - have found out that other people disagree."
Indeed, Luigs insists the High Island IV could work safely anywhere. However, he says, slant-drilling technology allows the rig to steer clear of delicate underwater environments like coral reefs.
Oil companies like to point out that, barrel for barrel, imported oil causes 20 times as much pollution as oil produced from the OCS. That's because imports arrive on tankers, which have more accidents than the pipelines that bring US production ashore. So offshore drilling, the industry insists, means less pollution rather than more.
It's an imperfect argument, though. No one claims that the OCS, which has produced 6.8 billion barrels of oil since 1954, has enough left to reduce imports significantly. And the nation's worst spill involved a tanker carrying US-produced oil out of Alaska in 1989. Presumably, oil found in Bristol Bay, even if taken ashore by pipeline, would then be shipped by tanker to the lower 48 states.
But how damaging are oil spills? Most remain offshore until they are cleaned up or dispersed naturally. And after 1993, the oil industry's Marine Spill Response Corporation will have personnel and equipment on standby in ports around the country.
When oil does reach shore, the consequences may be short-lived. Santa Barbara's offshore environment recovered within three years, according to a University of Southern California study. In Alaska, "clearly there is a lot of at least superficial evidence to suggest that it's not irreversible, that things are recovering," McManus says.
But some coasts are more susceptible to harm than others. A spill off Panama devastated a mangrove swamp and would similarly affect Florida mangroves and coral reefs, he says.
However, as time goes by, more of the energy produced from the OCS will be in the form of environmentally friendly natural gas - already two-thirds of the total, says MMS director Scott Sewell.
He says the barely drilled East Coast is overwhelmingly gas-prone. One lease off North Carolina that environmentalists want repurchased could alone contain up to 14 trillion cubic feet - equal to three-quarters of annual US consumption of natural gas.
A meeting in Houston last week illustrates the gap between advocates and opponents of offshore development. The OCS Policy Committee, which gives advice to the secretary of the interior, brings together representatives of MMS, coastal states, the oil industry, and environmental groups.
But the semiannual public exchange of views doesn't win environmentalists to the industry's cause. "I've watched this committee for 17 years. It's never accomplished a thing," says J. R. Jackson, a former Exxon manager who was instrumental in the discovery of the Prudhoe Bay field.
Nor does the secretary of the interior heed recommendations from the environmentalists. "The government is filled with advisory committees to give you the illusion that there's some kind of balance going on," shrugs McManus, who sits on the OCS committee. "Everything is a battle in the offshore."
Paul Rosanowski, a member who advises the governor of Alaska on environmental issues, says his state generally supports OCS development but opposes drilling in Bristol Bay at this time. The potential damage to the bay's $1 billion annual salmon harvest, the world's largest, isn't worth the risk, he says.
In citing Louisiana, Mr. Sewell says "there is absolutely no evidence that fisheries are harmed by OCS activities."
That fishery, one of the nation's most prolific, is "in pretty good shape," confirms William Herke, assistant leader of Louisiana Cooperative Fish and Wildlife Research Unit at Louisiana State University in Baton Rouge. "It's great fishing around the rigs."
Ironically, the fishery might eventually be harmed by the oil industry's onshore activity. Shrimp and other species use coastal marshes as a nursery. Those marshes are "falling apart," Dr. Herke warns.
Innumerable canals cut by oil companies admit saltwater that kills marsh vegetation. Then boat wakes erode the soil. Also to blame are the levees that prevent the Mississippi River from depositing more soil, Herke says.