Waves with heart-stopping 30-foot faces were expected to pound Northern California Sunday morning when the first heats of the Mavericks Invitational Contest kick off at Half Moon Bay.
"The waves are going to be insane ... and the level of surfing will break new ground," contest director Jeff Clark said in a statement announcing the event was on for the first time in three years.
An elite field of big-wave riders can expect roughly 30-footers all day at 18-19 second intervals Sunday, Stormsurf.com said Saturday. Some of the waves could be bigger, but a long wait between sets is likely.
The National Weather Service said boaters and people on shore needed to beware of large and dangerous shore breaks along the beaches and near channels and shoals.
Clark said San Mateo County authorities would close off beaches to the public as a precaution against rogue waves. The town of Half Moon Bay will hold a street festival featuring live music, a beer garden and live telecast of the offshore action.