Posted by on February 02, 2005 at 03:02:22:
In Reply to: Coast Guard to "protect" ports from scuba divers posted by on February 02, 2005 at 03:00:14:
WASHINGTON, Feb. 1 - Fearing that the nation's ports are vulnerable to an underwater attack, the United States Coast Guard is extending its domestic law-enforcement mission into a new arena: the sea below.
The Coast Guard's new tools include a new sonar-based device that can distinguish humans from aquatic life and underwater weapons that are being developed, including an air gun that sends a nonlethal acoustic impulse to force divers to surface by causing them discomfort, officials said.
Special 75-member Coast Guard law enforcement teams focusing in part on underwater security are also being set up in 13 ports nationwide. And the Coast Guard has acquired an underwater speaker system to blast verbal warnings to errant divers.
"Until now, we have had virtually no capacity to detect anything underwater," said Vice Adm. Harvey E. Johnson Jr., who is in charge of the Coast Guard's Pacific divisions. "It was a huge vulnerability. This is an attempt to narrow it."
The Coast Guard will unveil its new sonar device on Wednesday in Alameda, Calif. The move to extend the service's patrols from above the harbor to down below comes after a series of warnings issued that operatives of Al Qaeda have considered making underwater attacks.
After the 2001 terrorist attacks, the Federal Bureau of Investigation asked the nation's largest organizations that certify scuba divers to turn over records of every diver certified in the United States for the last three years. The extension of Coast Guard patrols underwater surprised leaders of groups that represent diving professionals. Jeff Nadler, vice president of PADI Americas, the world's largest diver certification organization, said on Tuesday that he was disappointed that his group had not been consulted.
"We certainly are very supportive of the need to take appropriate steps to protect the public against terrorist activities," Mr. Nadler said. "But what is the impact of high-frequency sonar on a individual who is diving? At this point, we don't know."
Coast Guard officials said they were confident that the equipment, if used properly, would not harm humans or aquatic life.
The Anti Swimmer System, the sonar detection system, consists of two sonars, one operated from the shore to provide basic surveillance of a 180-degree area covering several hundred yards and a second that is mounted on a vessel to provide detailed images of underwater objects.
The sonar, at least for now, will not be used for an entire port. Instead, the Coast Guard will respond to specific requests to monitor activity in relatively small areas near military ships, cruise ships or cargo ships. These patrolled sectors will generally be limited to areas where divers and swimmers are not allowed.
The shore-based sonar is hooked up to a computer developed by the Navy that can identify underwater objects and track their trajectory and speed, similar to radar systems used by air traffic controllers, said Lt. Cmdr. Alan Tubbs. It can distinguish between marine animals and humans in part because of their different shapes and typical movements underwater, he said.
If a suspicious object is detected, a Coast Guard patrol boat equipped with the imaging sonar will check it out. Crew members can wear a set of sonar projection goggles that would allow them to look deep into even cloudy water to see what is going on, Commander Tubbs said.
"We can put them anywhere we want, anytime we want," he said.
The sonars both operate at a high frequency that is not perceptible by most marine life, with the exception of bottlenose dolphins, said a Coast Guard spokeswoman, Jolie Shifflet. Whales, which are also sensitive to some sonar, should not be harmed because the devices would be used in harbors, not the open sea.
The underwater weapons, which the Coast Guard calls "nonlethal interdiction acoustic impulse" devices, are still being tested, so they will not be used immediately, Ms. Shifflet added. But several models use high pressure pulses of air or water to send shock waves through the water that feel something like the bass from loudspeakers at a concert.
The Coast Guard would use the devices only after issuing a verbal warning with the underwater speaker system, Commander Tubbs said. A single impulse would be sent first. But if necessary, repeated impulses could be sent.
In World War II, the Coast Guard used sonar to help protect military ships from attack. The United States Navy has also used sea lions and porpoises to help protect ships in the Persian Gulf from possible terrorist attack. The Coast Guard historically has also had dive teams that performed hull inspections and light salvage work. But officials said the collection of new equipment and the Marine Safety and Security Teams represented the first foray underwater within the United States.
Officials hope the new patrols underwater will discourage terrorists from considering an attack.
"You lock your door, turn on your lights and have a burglar alarm," Commander Tubbs said. "It is a deterrent."