Two recent cases regarding the Oil Pollution Act of 1990, known as OPA '90, will have a significant impact on the shipping industry.

One is Intertanko v. Locke, in which the U.S. Supreme Court will decide whether the U.S. Court of Appeals for the 9th Circuit erred when it ruled that Washington state regulations supersede federal regulations based on OPA '90's savings clause.In the other case, Alabama State Docks v. M/V Antares, the U.S. Court of Appeals for the 11th Circuit affirmed that a vessel is not a substantial threat to pollute merely because the Coast Guard says it is.

On Sept. 10, the Supreme Court announced several of the cases for which it will hear argument during the October 1999 term. Among these was the controversial decision of the 9th Circuit in Intertanko v. Gary Locke et al.

One of the key issues before the Supreme Court is whether the 9th Circuit correctly interpreted a clause in OPA '90 when it held that the Washington State Best Achievable Protection - BAP - regulations pre-empted corresponding federal regulations.

I submit that OPA '90 only allows states to impose regulations that set forth fines and penalties greater than the OPA '90 limits provided that there is a spill or substantial threat of a spill.

Intertanko is an international trade association whose 280 members own or operate more than 2,000 tankers of U.S.- and foreign-flag registry. In its appeal to the 9th Circuit of a decision involving the Washington rules, Intertanko cited 16 inconsistencies between BAP and existing federal regulations.

For example, BAP regulations require three licensed deck officers on watch during any period of restricted visibility. However, federal regulations as well as international law - note the international Standards of Training, Certification and Watchkeeping for seafarers - require only two. To conform with BAP regulations, a vessel operator will be forced to hire additional crew just to traverse Washington waters.

If the Intertanko decision is upheld, states will be permitted to use the 9th Circuit's misinterpretation of OPA '90 to promulgate their own vessel regulations.

In fact, some states already have. Rhode Island, for instance, has recently passed regulations (also based upon the same misreading of OPA) that impose additional requirements on tugboats and tanker barges traversing its waters. Similarly, California has also recently imposed its own Certificate of Financial Responsibility regulations.

In effect, the 9th Circuit's holding allows states to create and impose their own vessel regulations over and above the federal government. Such state regulations pose a dangerous threat to the uniformity of maritime law and the ability of our nation to participate freely in international commerce.

If the Supreme Court upholds the Intertanko decision, any vessel that calls in California, Washington or Rhode Island will have to conform to each of those individual states' regulations. Rather than increasing safety, this scenario will only prove to be hideously inefficient. It will not make vessels any more safe than the current federal regulations.

The other OPA '90 case is Alabama State Docks vs. the M/V Antares and Water Quality Insurance Syndicate. On Sept. 7, the U.S. Court of Appeals for the 11th Circuit affirmed the Alabama federal district court's decision. The lower court had held that the Coast Guard's stating in a letter that a vessel poses a substantial threat to pollute does not mean that it does so under OPA '90.

Alabama State Docks had sued the insurance syndicate directly as the pollution insurer of the Antares for wharfage fees that accrued against the vessel owner. ASD claimed that wharfage fees were recoverable as costs for mitigating a ''substantial threat to pollute'' under OPA '90.

The docks unit had relied heavily on two Coast Guard ''boiler plate'' letters sent to the vessel owner that stated that the Antares posed a substantial threat to pollute.

The court held that the letters merely described the vessel as ''unseaworthy'' and that it was never a ''substantial threat to pollute'' while it languished unattended at the Alabama State Docks facilities for 21 months.

ASD therefore, could not collect from the vessel's pollution insurers for wharfage.