The Southern California Coastal Ocean Observing System (www.sccoos.org) is one of 11 eleven regional associations developing an Integrated Ocean Observing System (IOOS) for the United States. IOOS is a recognized initiative identified in the U.S. Ocean Action Plan and is considered one of the U.S. contributions to the Global Earth Observing System of Systems (GEOSS). At the local level, SCCOOS works closely with regional and State mission agencies to develop science-based products to further their work. Agencies include seven different health agencies, three Regional Water Control Boards, major ocean dischargers that include sewer districts and municipalities, private industry including energy producers, marine safety officers, local Navy and Coast Guard personnel, and the commercial shipping industry. Federal funding is leveraged with existing projects with both the State Water Resources Control Board and the California State Coastal Conservancy, including a $21M statewide initiative to map ocean circulation, of which roughly half is invested in SCCOOS. We describe the history of SCCOOS and provide examples of activities presently underway.