Firefighters and lifeguards planned to resume searching Sunday for two men who were swept into the ocean off East Oahu during a high-surf advisory for south shores across the state.

Honolulu Fire Department spokesman Kendall Ching said the men, both in their early 20s, were near Halona Blowhole about 5 p.m. when a wave swept one man into the ocean. The second man was trying to help the first get back on land when he was also swept into the ocean by a wave.

Lifeguards said another person went into the water to help, but had to be assisted out by lifeguards.

Firefighters searched by helicopter and boat, and deployed divers until darkness ended the search at about 7 p.m. Ching said firefighters were hampered by rough surf and poor visibility in the water and did not find any sign of the men. A radio report said firefighters recovered a blue shoe in the area.

The Coast Guard also assisted in the search, launching an MH-65 Dolphin helicopter and a 45-foot response boat. The Coast Guard planned to search overnight with the helicopter and an 87-foot patrol boat.

The high-surf advisory kept firefighters and lifeguards busy with rescues on Saturday.

Lifeguards made 21 rescues on the south shore and 18 rescues on the west side by 4:45 p.m. Saturday, according to Shayne Enright, Honolulu Emergency Services spokeswoman. Lifeguards also made 3,000 preventive actions on south and west shores.

“To say it was busy was an understatement,” Enright said. “It was busy everywhere (on all shores).”

Ryan Moniz, a lifeguard at Kaimana Beach in Waikiki, said lifeguards were dealing with the swell along with the “sheer number of people” on the beach during the weekend. Lifeguards on personal watercraft patrolled the surf along Waikiki and were helping people in the water in distress, he said.

Along Waikiki’s shore, a hazy sea spray from the pounding surf filled the air.

Lifeguard Matt Arakaki said he saw a couple broken surfboards, including one belonging to a surfer who couldn’t swim back to shore from about 400 yards out. Arakaki said he saw the man waving his board and radioed another lifeguard on a personal watercraft to bring the man back to land.

The swell, generated by a low-pressure system near New Zealand, is expected to be long-lived with surf reaching 8 to 12 feet through Sunday, the National Weather Service said. The high-surf advisory is set to expire at 6 a.m. Monday.

The weather service warned beachgoers to heed the advice of lifeguards, exercise caution, and expect strong breaking waves and rip currents that make swimming dangerous.

Lifeguards and firefighters were still making rescues at the end of the day. About 6:30 p.m., lifeguards rescued four people in the ocean off Makaha and several people off Yokohama Bay.

About 8 p.m., firefighters were dispatched to a report of two overdue surfers off Kuliouou. They were found.

“Be cautious,” Enright said of the high surf and rough conditions. “Know that the risks are serious and life-threatening.”