There are 3 cruise departure ports in California. Two in Southern California and one in Northern California. These other sites provide detailed information.
Los Angeles Cruise Guide: Short cruises to Mexico depart constantly from LA. Other itineraries include Hawaii, South America, and world cruises.
San Diego Cruise Guide: Cruise out of San Diego on a voyage to Mexico, Hawaii, the South Pacific islands, South America or the Panama Canal.
San Francisco Voyage: Several cruise lines offer trips out of San Francisco. Destinations include Alaska in the summer and Hawaii in the winter. There are also cruises to Mexico, Australia, and through the Panama Canal.