SAN FRANCISCO (KTVU) - They are big, powerful, frequent, and at least one of them was destructive.
In Rockaway Beach in Pacifica, a huge wave came up and over a railing, traveled some 40 feet and knocked out a window of the Lighthouse Hotel.
"Just crashed it out. All the way to elevator machine room," said Manuel Rodas, the hotel engineer.
The Moonraker Restaurant which sits above the hotel was not damaged.
But waves splintered off two of the hotel's columns. There is also water damage.
"Carpet walls drapes. Table cloths. Whatever was inside is ruined," said Rodas.
The National Weather Service predicted breakers of 25 to 40 feet. Some over 50 feet.
For the most part the big waves today are a local attraction, even if the Pacifica Pier was closed today out of safety concerns.
"It's not usually this white here. All foamy. There's a lot of frequency. And splash," said Luana Turovskaya of Pacifica.
But for those living across the street from the ocean, the waves are are a force to reckon with .
"The garage door slams. I can't leave the car inside. I'd be trapped. So I have to park outside," said Jioconda Egan.
At Ocean Beach in San Francisco authorities are advising people not to even stand on the sand.
But people did just that.
"We want to spread the word to let the public know this is very serious. And there conditions where our rescue workers may not be able to go into the water to rescue. That's the biggest issue out of all of them," said Lt. Jonathan Baxter, a SF Fire Department spokesman.