WASHINGTON — Members of Congress, hearing horror stories yesterday about crime aboard cruise ships, said legislation might be needed to guard against lawlessness on the open seas.Opening a hearing by the House Transportation maritime subcommittee, Rep. Elijah Cummings, D-Maryland, said many Americans do not understand the potential legal complexities that can surface in connection with crimes that are committed on cruise ships travelling outside US territorial limits.

Cruise ship operators announced at the hearing a voluntary new agreement with the FBI and the Coast Guard to improve and standardise crime reporting. According to the FBI, cruise ships don’t have to report violations of US law outside US waters, 12 miles offshore, but under the new agreement they would do so immediately.

“The industry has an enviable record when it comes to safety and security,” said Terry Dale, president and chief executive of the Cruise Lines International Association. “The industry has a zero tolerance for crime.”

Several lawmakers suggested the crime-data reporting needs to be mandatory, not voluntary. FBI and Coast Guard officials praised the new steps but described complex jurisdictional problems because the vast majority of cruise ships fly under foreign flags and therefore aren’t under US jurisdiction once they leave US waters. US authorities can’t often board them without permission.

“The jurisdiction issue is very tricky and a tangled web,” said Salvador Hernandez, a deputy assistant director at the FBI.

A briefing memo prepared by Transportation Committee staff described current record-keeping on cruise ship crime as spotty, noting the FBI does not keep data on the total number of alleged crimes reported on cruise lines but only on cases for which it opens files — 50 to 60 per year. The FBI said that under its new agreement with cruise lines it will keep track of all crime reports.

Laurie Dishman, 36, of Sacramento, California, wept as she told the panel that she was raped last year aboard a Royal Caribbean cruise to the Mexican Riviera, by a cruise ship employee.

“The terror of that experience still overwhelms me,” said Dishman, but what happened next was almost as bad. She said the cruise line did little to respond and gave her a garbage bag, telling her to collect evidence from the scene herself.

“The feeling was like nobody was helping me,” she said. “Everything was slow-motion and they were trying to figure out how to protect themselves.”

Gary Bald, senior vice president of global security for Royal Caribbean Cruises Ltd., acknowledged problems in the cruise line’s response to Dishman and said the company has improved security and has taken steps to ensure that in the future, victims are given better information and support and crime scenes are secured.

The cruise line determined that the employee who allegedly committed the assault had violated policies about fraternising with guests and drinking on duty, and he was fired.

“It was our intention and desire to assist her in every way we could,” Bald said. “I feel we accomplished that in some respects but in others I feel we came up short.”

After the ship docked in Los Angeles, the FBI presented Dishman’s case to the US attorney who chose not to prosecute for lack of evidence.