The 9/11 attacks proved that terrorists can use virtually any vehicle to strike.

Small boats are no exception. And experts agree they will remain a weapon of choice in the maritime environment, given their low cost, ease of deployment and success record.

“I have believed for the last two years since I’ve been commandant that the small vessel threat is something that we need to look at and consider more seriously,” said Coast Guard Adm. Thad Allen.

Small boats can hide in the clutter of military, commercial and recreational vessel traffic at U.S. ports, where unregulated pleasure craft buzz near high-profile military and commercial ships — prime targets for terrorists.

In the past, local law enforcement was tasked with defending ports from small boats. Now DHS is moving toward more interagency cooperation and an increased use of technology to tackle the threat. But its plans are no silver bullet, and recreational boaters fret over the consequences.

Small boats provide terrorists with a myriad of options. They could be used in suicide attacks, as was the case in 2000 when al-Qaida operatives in Yemen rammed an explosives-laden dinghy into the USS Cole, killing 17 U.S. sailors. They could attack ships docked at shore, entering ports or sailing off the coast. They could deliver nuclear, biological, chemical or radiological devices, or be used to mine harbors, wrote James Carafano, senior fellow at the Heritage Foundation, in a paper entitled, “Small Boats, Big Worries: Thwarting Terrorist Attacks from the Sea.”