The Coast Guard, along with US and allied partner agencies, has increased its presence in the Eastern Pacific Ocean and Caribbean Basin as part of its Western Hemisphere Strategy. During at-sea interdictions of these known drug transit zones, a suspect vessel is initially located and tracked by allied military or law enforcement personnel. The interdictions, including the actual boarding, are led and conducted by US Coast Guard personnel. The law enforcement phase of counter-smuggling operations in the Eastern Pacific is conducted under the authority of the 11th Coast Guard District, headquartered in Alameda, California.