The main point of the 9/11 warning scandal is that relevant information didn't get to the right people. But it's also bad when the government makes an effort to get irrelevant information to the wrong people: It distracts counterterror professionals from more productive pursuits and pointlessly terrifies the rest of us. The government's recent warnings about possible terrorist scuba divers—warnings not based on specific leads—are an excellent case in point.
The warnings, which were issued to the general public as well as to dive shops and operators of bridges and maritime businesses, suggest that the government's counterterror folks don't know a whole lot about diving as a threat. In the absence of specific intelligence, I'd hate to think that U.S. agents are spending too much shoe leather on this instead of on, say, truck- and pipe-bombers, because:
Underwater demolition is much, much harder to bring off than the terrestrial kind. All a pedestrian suicide bomber needs is a bomb and the will to set it off. The only other thing a car- or truck-bomber needs is a vehicle. However, a scuba bomber would not only have to be a skilled diver, but would also have to know how to move his bomb load—most likely a package of explosives too heavy to carry on his back—despite its potential to trap him on the surface or drown him. The extra skills required to do this are taught at the military dive schools attended by such elite types as SEALs and Green Berets, and at industrial dive facilities, but not at your neighborhood recreational dive shop. And detonating explosives underwater effectively requires more special training and equipment than doing so on land. Therefore, investigative legwork on the scuba threat should be limited to military-caliber dive training and those who've had it or asked about it.
Underwater attacks mean smaller blasts than terrestrial ones. The amount of explosives a team of divers can deliver pales in comparison to what cars or trucks can carry. "Because you would need several thousand pounds of explosives to go against a major bridge from underwater, they are not a practical target for a scuba team," says Bob Bevelacqua, who used to command a Green Beret scuba detachment. To make even the slightest dent in this problem would take military gear like swimmer-delivery vehicles, mini-subs, and full-size subs, things that are considerably rarer and hence easier to monitor than basic scuba gear.
Evenif you take the scuba problem seriously, then U.S. dive schools and shops are a very small part of the problem. You can get certified as a recreational diver at schools all over the world, and once you do, you receive a card that entitles you to get a wide variety of dive equipment anywhere—including in the United States. No matter how many FBI agents canvass U.S. dive schools, there are shops in Mexico, the Caribbean, and Egypt (to name a few of the world's top dive resort areas) that could have already issued those cards to would-be bombers, who could then easily and quickly get access to equipment here.
In light of these facts, don't you have to wonder about the government's grasp of homeland defense priorities?