This article briefly describes marine policing experiences, focusing primarily on the U.S. Coast Guard and the New York Police Department's Harbor Unit. Similarities and differences between sea and land policing are explored. The jurisdictional nature of the NYPD Harbor Unit and the Coast Guard are assessed. Although the Coast Guard has jurisdiction throughout the U.S., some areas have exclusive State jurisdiction, and the local authorities, such as the NYPD Harbor Unit, take over. Primary activities of the Coast Guard include illegal/illicit drugs trafficking, illegal aliens, recreation and boating safety law violations, and intoxicated operations. The author concludes that regardless of who does what where, or who has jurisdiction, the bottom line is that law enforcement on the high seas is law enforcement. The marine patrols comprise an integral part of the law enforcement effort.