A high-surf advisory for O'ahu's south shores has been extended until 6 p.m. today, the National Weather Service said.

Waves of 8 to 10 feet were reported at beaches in Waikīkī and Ala Moana yesterday.

The southern swell is the effect of several large storms near New Zealand that were moving east about a week ago.

The National Weather Service said March is the time of year for southern swells and described the present situation as "fairly typical."

Forecasters last night said the swell was starting to decline and the advisory may be ended earlier than this evening.

There were just a handful of water rescues and assists on the south shore yesterday, said city Department of Emergency Services spokesman Bryan Cheplic.

"It wasn't that busy," he said.

That's in contrast to the situation Saturday, when lifeguards in the Ala Moana-Waikīkī area made five rescues, 28 assists using jet watercraft and took more than 500 preventive actions.

Meanwhile, a man in his 60s was injured about 10:45 a.m. yesterday when he jumped off the Kapahulu groin, known as the "Wall," in Waikīkī.

Lifeguards pulled him from the water, and he was taken to a hospital in critical condition.

The wall is a popular jumping off point for swimmers and bodyboarders.