USA. California. Los Angeles. LA Harbor. From the police boat patroling the harbor. The ports of Los Angeles and Long Beach are the gateway for 42% of the cargo coming into the U.S. Los Angeles is one of the busiest seaports in the world, is located in the San Pedro Bay at the southernmost point of Los Angeles County, approximately 20 miles from downtown Los Angeles. Because of its proximity to the Pacific Ocean, the San Pedro Bay has a long history of maritime activity. 2004.