Oil oozes from the single-hulled Exxon Valdez in 1989

Poor Exxon. The biggest profits in the history of the world must, unfortunately, not be enough to cover the cost of using tankers that virtually eliminate oil spills. And of course Exxon, which was responsible for the country’s largest oil spill, is all about avoiding them in the future. Or not.

On March 24, 1989 — 20 years ago exactly — the Exxon tanker Valdez dumped 11 million gallons of oil into Prince William Sound and along 700 miles of its coast, killing tens of thousands of marine animals and birds, and mostly wiping out the sound’s then-thriving commercial fishing industry.

The company got off light, by filing endless appeals to its award of punitive damages (the type of damages intended to teach a lesson, as opposed to compensatory damages which should only repay financial costs), and by throwing the ship’s captain, a recovering alcoholic, under the bus.

On June 25, 2008, the U.S. Supreme Court rendered an opinion permitting the assessment of punitive damages…However, the Court held that the punitive damages award against Exxon was excessive and should be limited to $507.5 million, an amount equal to the trial court’s calculation of appropriate compensatory damages.

While $507.5 million sounds like a lot to you and me, for Exxon, it’s just an oil drop in the bucket. Recall that this company’s earnings in 2007, when gas hit $4 per gallon, was $40.6 billion. That record was broken last year, when Exxon posted $45.2 billion for 2008.

So you’d think they could afford to join almost every other oil refiner in using double-hull tankers. You’d be wrong.

Even after 79 percent of the world supertanker fleet has been replaced by craft with two hulls, Exxon Mobil Corp. remains the biggest Western user of the older designs. It hired more of the tankers last year than the rest of the 10 biggest companies by market value combined…

Exxon, the world’s largest oil company, has kept using tankers with one hull even as 151 countries have decided two are better than one for preventing oil spills and pledged to ban single-hull vessels by 2015. The European Union called the design “more accident-prone” in 2003, when it started a prohibition that takes full effect next year. London-based BP Plc says it won’t hire them because of the risk of leaking…

Double-hull tankers have an outer layer of steel, normally about an inch thick and 6.5 feet from the inner one, that acts as a buffer in an accident. When tankers with one shell are ruptured, the only place for the oil to go is into the sea.

But if poor Exxon embraced new methods it would cut into their profits just the weensiest bit on the front end, even if it could save them boatloads more on the back end.

It costs about 20 percent less to hire a single-hull ship. Exxon’s estimated savings amounted to less than a cent a share last year, according to Bloomberg calculations…

Exxon saved an estimated $18 million last year using single-hull vessels…Hiring a double-hull replacement for SeaRiver Long Beach [the sister ship to the Valdez] for a year would have cost about $25 million…

Apparently the punitive damages, which the Supreme Court converted into only compensatory damages, weren’t enough to drive the message home to Exxon that oil spills aren’t O.K. Bush I appointee Justice David Souter wrote the opinion for the court and was joined by Roberts (Bush II), Scalia (Reagan), and Thomas (Bush I). Alito (Bush II) abstained.

For its part, Exxon claims it’s not about the money but declines to offer further explanations. No one else can think of alternate defenses.

“We in the market don’t understand why Exxon continues to do this,” said Per Mansson, a shipbroker at Nor Ocean Stockholm AB, who’s been involved in the tanker industry for 30 years.