When cruise ship owners held their convention in Miami earlier this month, one of their greatest concerns was the National Transportation Safety Board's moves to investigate cruise ship accidents -- no matter what flag the ships fly if they call at U.S. ports.

A letter to participants called the board's efforts "the most difficult challenge facing the cruise ship industry," and said "this trend has far-reaching implications that nobody in the cruise industry can afford to ignore."

So who did they ignore? James L. Kolstad, chairman of the National Transportation Safety Board.

In April, he had accepted an invitation to speak. His speech was being written. But on Sept. 21, six weeks before the event, the invitation was withdrawn.

Left on the program was a representative of the Coast Guard, which disagrees with the board's position. Replacing Kolstad was an attorney who is helping fight the board's efforts to increase its jurisdiction.

The board has become increasingly active on cruise ship safety, given that 80 percent of cruise ships operate out of U.S. ports. However, none of those ships fly the U.S. flag, meaning the board has no specific authority to investigate accidents once they leave territorial waters. The board has gone to court in an attempt to gain authority.

The only reason that the conference organizer, Marine Log of New York, a cruise ship industry newsletter, gave Kolstad was that "recent and crucial developments in the courts mean that we now have to devote a larger part of our program . . . to legal topics." A spokesman for Marine Log was out of town and could not be contacted, according to an aide at the organization.

Kolstad replied to Marine Log in a letter that began "Dear Friends," and stressed cooperation in enhancing cruise ship safety. He listed a number of the board's concerns, including: elimination of language barriers between crew and passengers, making life jackets available at all muster stations, and improving sprinkler systems and fire-fighting training.

"The participation of the safety board in accident investigations can only help strengthen your stated interest in safety," he said.

A board spokesman, Alan M. Pollock, said the canceled invitation only increases the board's determination. "The cruise ship lobbyists really shot themselves in the foot this time," he said.