The video shows a blue whale approaching a boat, dwarfing it in size.
The owner of the whale watching company says the engines were off and the boat was just drifting when the whale came in for a closer look.
He says they have been lucky to spot blue whales almost every day for the past week.
The giants typically spend the summer months feeding on the abundant supply of krill off the coast of California.
Bear attacks 19-year-old woman taking nap in backyard in Southern California
Bear attacks 19-year-old woman taking nap in backyard in Southern California