Experts who track the animals say most of the sightings have been of the same two family groups traveling along the coast looking for seals and sea lions to eat.
Diane Alps, president of the American Cetacean Society's Los Angeles chapter, spotted about 10 whales on Sunday and Monday
The whale-watching vessel Dana Pride spotted seven to 10 of the whales Tuesday off the Orange County Coast near Dana Point.
Experts say seeing killer whales off Southern California is a once-in-a-lifetime experience.
They believe the whales are part of a transient population of orcas more commonly seen near Monterey Bay on the Central Coast.
The pod includes seven whales from one family, known as CA 51, and three from another family, called CA 140, according to the California Killer Whale Project.
In the last month, the same whales were seen near the Channel Islands and off the coasts of Ventura and Newport Beach. They were also back in Monterey Bay, for a time.