The National Transportation Safety Board, in an effort to prod the Coast Guard to gain control over state-licensed ship pilots, is steering into heavy waters because of almost two centuries of judicial precedent and clannishness among a group of stubborn men.

After a 15-month investigation into the river pilots who operate essentially as closed societies on the Mississippi River, the safety board concluded that the pilots need outside supervision. The board recommended that the Coast Guard seek legislation creating a federal pilot's license superior to all state-issued licenses, which, in effect, would give the agency the power to regulate and discipline pilots.

The case indicates once again that the federal government is not all-powerful, that even when it makes up its mind to take action, it is often tied in knots by tradition, precedent, state law and just plain orneriness on the part of organized groups.

"The NTSB's answer to everything is more regulation," said a former Coast Guard accident investigator who asked not to be named because he is involved in litigation on the Mississippi. "The Coast Guard may not think more regulation is the answer to everything. The NTSB is seen by the Coast Guard as 'Uh-oh, here come the out-of-town experts.' "

Pilotage is not a new issue. It is complicated by a thicket of state regulation and judicial caselaw, and the Coast Guard has not previously sought to try to turn that tide. States have reserved the right to control pilots on bays, inlets, river, harbors and ports within their territorial limits.

This dates back to 1789 when the first Congress gave control of pilots to the states as an issue of commerce. Since then, pilot associations, with various by-laws and rules, have grown up in 22 coastal states.

In most cases, pilots hold dual licenses -- a federal pilot's license, issued by the Coast Guard, and a state license. With a federal license alone, a pilot can operate domestic vessels traveling between U.S. ports. The bulk of the shipping trade, however, involves foreign ships.

Most states require new candidates to hold a federal pilot's license to qualify for a state pilot's license. Cub pilots are then required to complete an apprenticeship under supervision of the local pilots.

"You could be the worst ship handler in the world and the Coast Guard wouldn't know it," said the former accident investigator. "But the apprenticeship technique will determine if you have hands-on skills, docking and undocking a ship, making it through the fog."

The Coast Guard tried twice in the 1970s to take action against pilots' federal licenses, but was defeated both times. The first case involved a September 1967 collision between a Japanese log ship and another ship in a dense fog in Puget Sound near Seattle.

The Coast Guard faulted the pilot of the log ship, Capt. Dewey Soriano, and tried to suspend his license for 12 months. Soriano appealed to the courts, and in 1974, the 9th Circuit Court of Appeals in San Francisco found that Soriano was operating the ship on his state license and the Coast Guard did not have jurisdiction over it.

The Coast Guard lost again in 1976, when it tried to suspend the license of a Mississippi River pilot for three months.

"When you litigate against pilots, you get this stuff thrown back at you from Supreme Court decisions," said a Washington maritime attorney who represents barge and shipping interests. "It makes you think they walk on water."

The Coast Guard has the power to assess a civil penalty of $1,000 against pilots found negligent in accidents. But, in practice, many of the penalties are fought out in court.

For instance, the Coast Guard finally collected a $500 fine from the pilot who rammed the Sunshine Bridge in Tampa Bridge -- six years after the accident.

"As a matter of practice, all these things are appealed by pilots associations and they get to federal court," said Werner Siems, the Coast Guard's chief spokesman.

The pilots, who in most states investigate their own accidents, say they are best qualified to do so because they are the local experts who understand the local waters, currents and tides. For example, the pilot who rammed the West Seattle Bridge in the late 1970s was never disciplined. But he never piloted another ship.

To involve the Coast Guard more deeply in ship accident investigations would involve more manpower and more expertise. Ship accidents are often investigated by young officers who have not been in the district very long, and pilots complain the investigators often do not know what they are doing.

"There's a lot of blameless ways to get into trouble on the river and a lot of blameworthy ways," the former investigator said. "The trick is knowing the difference."