SAN DIEGO (CBS NEWS 8) - For some local whale watchers this past week has been a memorable one. 

Pods of whales sometimes in groups of 10 or 20 have been spotted just off the coast of San Diego in so-called feeding frenzies. Experts say the sightings are rare.

"We haven't had a week like this last week in a long, long time."

Russell Moore runs a whale watching company called Xplore Offshore.

Over the course of three days, he spotted dozens of whales in feeding frenzies, between three and five miles off of Pacific Beach.

The various species were eating krill that made it's way to the surface -- something few people get a chance to witness.

"This was a phenomenon based on the still water pattern or the right current that the krill and all this was on the surface and the whales were gorging it like a buffet table."

Other companies reported seeing the same thing -- including San Diego Whale Watch.

"We had all four feeding at the same we had blue whales, minky whales, humpback whales," said Chris Switzer.

CBS News 8 showed the images to Birch Aquarium at Scripps' executive director Nigella Hillgarth.

"I hadn't heard of people seeing these feeding frenzies before," Hillgarth said. "Normally we see a lot of whales migrating past San Diego, not stopping to feed."

Hillgarth says surface feeding rarely occurs so close to shore but if you want to try your luck -- now is the time to do it.

"Well, we know the blue whales are staying around are really searching for where the krill is, and so you're more likely to see this when you go whale watching."

"You don't have to go to don't have to go to Antarctica. When this stuff happens, it's happening right here," said Moore.