Sometime after The San Diegans were extended to Santa Barbara (I don't know the exact time frame), and perhaps around the same time that California Department of Transportation (Caltrans) funding increased, the service was renamed Pacific Surfliner, given that there is a significant amount of running along the coast, some of it almost right up to surfline along the beaches. It was also about this time that the "Amtrak California" moniker was introduced and applied to the Surfliners and the Capitol Corridor trains in Northern California. Any corrections and elaborations would be welcome.