In recent days, a flurry of great white shark sightings between Monterey and Santa Cruz has put both beach goers and marine biologists on alert.
The great white is both a feared predator and a vulnerable endangered species.
One sighting was just off Capitola on a boat Sunday, about 200 feet from bathers on the beach who were oblivious of the shark.
Naturalist Kate Cummings, who works with Blue Ocean Whale Tours, took a number of photos from only six feet away.
"Just to see this silhouette of a great white shark next to the boat...it was surreal," said Cummings.
Many sightings of great whites have been made from aircraft since Friday, including one spotted close to shore near the pier at Sea Cliff State Park.
The sharks come here every year the same time of year same season, explained Sean Vansommeran of the Pelagic Shark Research Foundation.
Watsonville's Specialized Helicopters runs aerial shark tours of the region.
When the water's clear we see them. When it's not we don't, so they're there at all times during this time of year, said Specialized Helicopters’ Chris Gularte.
Vansommeran showed KTVU video of him tagging great whites in order to better understand their behavior and how to protect them.
These sharks are vulnerable, said Vansommeran. Poaching, commercial fishing, incidental take have all increased in recent years.
Great whites are blamed for four California deaths in the last decade.
Experts recommend always surfing with a buddy and staying aware of your surroundings whenever in the water.
"If you ever see a large animal that's out of place, unusual or maybe threatening, report that immediately to rangers and lifeguards," said Vansommeran.
Shark experts call the area where great whites gather stretching from Point Reyes down to Monterey Bay and out to the Farallon Islands the Red Triangle. The peak time begins next month, which researchers commonly refer to as 'Sharktober.'
Watchdogs are questioning an exclusive agreement between the City of Oakland and a non-profit group, tapped to lead a multi-million dollar project to redevelop the area around the Coliseum BART station.