From the Facebook of Hornblower Cruises, whose captain spotted the massive pod:
EXCITING Whale Report just in from Capt. Joe Dutra who is a veteran Hornblower leader working on the water for over 40 years. Capt. Joe reported a super mega pod of common dolphins, a size of which he has never witnessed before off the coast of San Diego. He said the pod was over 7 miles long and over 5 miles wide. He said he is not one to exaggerate and that he estimated the pods at "hundreds of thousands" in size! "The ocean was literally white from the wash of frenzied dolphins and birds feeding on the swarming bait below!"