Oahu lifeguards rescued 26 people and issued more than 4,300 warnings as big waves of 20 to 30 feet rolled in to the North Shore.
Meanwhile, the National Weather Service extended a high surf warning through 6 a.m. Tuesday.
The warning had been scheduled to end at 6 p.m. for north and west shores of Oahu, Kauai County and Molokai and for north shores of Maui.
A high surf advisory for the Kona and Kohala area, where 8-foot surf was expected, was also extended to 6 a.m. Tuesday. Forecasters said the swell would decline tonight, but will remain at warning and advisory levels.
“Large breaking surf, significant shorebreak and dangerous currents make entering the water very hazardous,” forecasters said. “Anyone entering the water could face significant injury or death. Beachgoers, swimmers and surfers should heed all advice given by ocean safety officials.”
On Oahu’s North Shore, lifeguards resued 13 people and issued nearly 4,200 warnings.
Shayne Enright, an Ocean Safety spokeswoman, said lifeguards rescued 8 people at the surf break known as Himaylayas and more than 2,000 people were warned about the dangerous shorebreak at Sharks Cove and Three Tables.
West-side lifeguards rescued another 13 people and issued 131 warnings.
The National Weather Service said surf on north shores was expected to lower to 10 to 15 feet on Tuesday.
West shores were expected to peak at 15 to 25 feet, then lower to 8 to 11 feet on Tuesday.
Another northwest swell is possible Friday and could bring more advisory-level surf. Warning-level surf could return this weekend.