Book excerpt: Since the terrorist attacks of September 11, 2001, maritime security efforts have focused primarily on large commercial vessels, cargoes, and crew. Efforts to address the small vessel environment have largely been limited to traditional safety and basic law enforcement concerns. Small vessels are, however, readily vulnerable to potential exploitation by terrorists, smugglers of weapons of mass destruction (WMDs), narcotics, aliens, and other contraband, and other criminals. Small vessels have also been successfully employed overseas by terrorists to deliver Waterborne Improvised Explosive Devices (WBIEDs). Law enforcement agencies face the challenge of distinguishing between the vast number of legitimate vessel operators and the relatively few individuals engaged in illicit activities. The challenge is immense, as it involves nearly 13 million registered U.S. recreational vessels, 82,000 fishing vessels, and 100,000 other commercial small vessels. On any given day, a considerable number of these boats share waterways with commercial and military traffic, operating at hundreds of U.S. ports and in the immediate vicinity of critical maritime infrastructure, including bridges and waterfront facilities such as petrochemical plants. More information concerning small vessels is needed to improve the proper assessment of the risk posed by these vessels. The challenge is to balance the collection of requisite information necessary for proper assessment of risk posed by these vessels, with the freedom of the seas expected by the small boating community.