Spring cruises departing out of SD go to Hawaii, the Mexican Riviera, South America, through the Panama Canal, and up the Pacific Coast. Unfortunately, there are no summer cruises from this port. In the fall, cruises go to Australia as well as Mexico, South America, Hawaii, and nowhere. Winter cruises go to the Mexican Riviera and through the Panama Canal.
For more departures from Southern California, check the cruises out of Los Angeles. That port isn't far from San Diego.