HALF MOON BAY -- The same ocean conditions that will yield the Mavericks Invitational will cause dangerous surf conditions in the Bay Area this weekend, and officials are urging beachgoers to be cautious.

The National Weather Service has issued a high surf advisory from 10 a.m. Saturday to 4 p.m. Sunday, leading the Coast Guard and National Park Service to warn people who visit area beaches or operate boats near the shore to be careful.

Officials are predicting waves as high as 8 to 10 feet. People who walk along the beach should stay away from the water line and never turn their back on the ocean.

Some beaches, such as those in Point Reyes National Seashore, are prone to "sneaker" waves -- strong surges of water that arrive unexpectedly.

"The big thing is for people to constantly be aware of what's going on around them," said Coast Guard Lt. j.g. Joshua Dykman. "Those waves can come up and sneak up on you, and that current can take you out pretty quickly."

Jeff Clark, organizer of the Mavericks big-wave surfing contest Sunday north of Half Moon Bay, said conditions will be "lully." In other words, there will be hard-to-predict lulls in between sets of waves. The waves at Mavericks are expected to be in the 30-foot range.

Contact Aaron Kinney at 650-348-4357. Follow him at Twitter.com/kinneytimes.

If you go
What: Mavericks Invitational Festival
Where: Grounds of the Ocean Hotel & Spa, Princeton-by-the-Sea
When: 8 a.m. to sunset Sunday
How much: General admission tickets are $10 in advance and $20 at the gate; VIP tickets are also available
Parking: Available for $15 at Half Moon Bay Airport on state Highway 1; from there visitors walk to the festival grounds
Tickets and information: www.mavericksinvitational.com