WASHINGTON – The Coast Guard will begin testing in February a new way to prevent terrorism on the seas: radio receivers on weather buoys ringing the U.S. coast that can track ships long before they reach ports.

A law passed after the 2001 terrorist attacks requires large vessels to have transponders by year’s end that emit unique radio signals.

But only 10 stations can receive the signals – far too few to monitor the nation’s 12,375 miles of coastline and 25,000 miles of river or inland shoreline, according to a Government Accountability Office report in July.

The report said vessel transponder signals can’t be received by many of the nation’s major ports, such as Boston, Baltimore and Charleston, S.C. Facilities to receive the signals haven’t been finished in Puget Sound and San Francisco, the report said.

Jeffrey High, the Coast Guard’s director of maritime domain awareness, told a congressional committee Wednesday that the Coast Guard plans to expand radio coverage by installing receivers on 70 buoys that send weather and environmental information to the National Oceanic and Atmospheric Administration’s data center.

“We just looked at them and saw they’re a natural location to create a picket line,” High said.

The data center can forward the identity and location of vessels to the Coast Guard, which can tell other agencies, High said.

Presidential candidate John Kerry and congressional Democrats have said the Bush administration is lax on port security, with only a small percentage of containers inspected for chemical, biological or radioactive weapons.

Oregon Democrat Peter DeFazio, who serves on the House Coast Guard and Maritime Transportation subcommittee, said there are too few inspectors to make sure ships aren’t vulnerable to terrorists.

“Osama bin Laden could own ships and we probably wouldn’t know,” DeFazio said.

The weather buoy system will be similar to one used by the Federal Aviation Administration to track aircraft.

Deviations by ships could indicate terrorist activity, High said, adding that the Coast Guard is trying to discern what anomalies to look for.

High said the Coast Guard should be able to receive vessel transponder signals along the nation’s entire periphery by 2008.

Receivers generally can pick up signals from a radius of 10 to 20 miles, and some from as far away as 40 miles, High said.

That’s not enough for subcommittee Chairman Frank LoBiondo, R-N.J. “We must be able to extend our tracking capabilities beyond the range of this system,” he said.

The Coast Guard plans to test how a receiver would work from a low-flying satellite in December 2005, High said.