The basic requirement of the Lightering Zone Enforcement Mission is the capability to survey lightering zones and conduct boardings as necessary. 

Lightering Zone Enforcement. The Oil Pollution Act of 1990 restricts oil tankers not equipped with double hulls from many U.S. ports, thus requiring such vessels to lead cargo in off shore lightering zones. The basic requirement of the Coast Guard's Lightering Zone Enforcement mission is the capability to surveil lightering zones and conduct inspections as necessary. Seventy-four percent of the nation's crude oil imports were received in Gulf of Mexico ports, and twenty-nine percent of this was lightered.