RAND cites threats for ferries, cruise ships.

While the recently signed Port Security Improvement Act of 2006 has numerous provisions for inspecting inbound shipping containers, a Rand Corp. report suggests that ferries and cruise ships are easier and more likely terrorist targets.

"Maritime Terrorism: Threat, Consequences and Liability" examined the likelihood and impact of scenarios involving container and passenger ships. Its conclusion: while a nuclear weapon detonated in a U.S. port would have the greatest impact on human life and the economy, attacks on cruise ships and ferries would be relatively easy to carry out with conventional explosives or biological agents.

"Cruise ships in many ways resemble hotels, which terrorists have attacked in the past," Henry Willis, a Rand researcher and co-author of the report, said at a congressional briefing.

Ferries are particularly vulnerable because of the speed in which companies must board passengers, cargo and vehicles. All may contain hidden explosives. This leaves little time for inspection. Because of modern hull design, it would be difficult to use an improvised explosive device to sink a cruise or container ship, but cars parked in ferries tend to sit low on the water, he said.

"Attacks on ferries are easy to execute, have the potential to kill many people, are likely to capture significant media attention and can be exploited to visibly demonstrate a terrorists group's salience," the report said.

The February 2004 bombing of the Super Ferry 14 in the Philippines cost the perpetrators about $300 in explosives. The attack killed 116 and wounded more than 300, the report noted.

The port security act called for a plan to be in place by April 2007 to inspect passengers and vehicles bound for the United States aboard ferries. This would mostly affect U.S.-Canadian crossings.