The U.S. Coast Guard, Honolulu Fire Department and Ocean Safety and Lifeguard Services crews conducted joint training on Oahu’s North Shore Tuesday ahead of the island’s famed annual high surf season.

The three agencies are the primary responders to incidents in the approximately 7-mile surf zone off Oahu’s North Shore which draws surfers from all over the world every winter. The swell can reach heights of more than 30 feet and is very dangerous, even for experienced surfers.

Two Coast Guard MH-65 Dolphin helicopters from Coast Guard Air Station Barbers Point, an HFD helicopter with small boat crews and three Ocean Safety rescue craft operators participated in the event off Haleiwa, with the focus of operating together to rescue a person in trouble in high surf conditions.

Residents and visitors alike are encouraged to check conditions, available by speaking with lifeguards or at www.hawaiibeachsafety.com, prior to engaging in ocean activities and to heed the advice of ocean safety personnel.

A high surf advisory remains in place for north- and east-facing shores of Kauai, Oahu, Maui, Molokai and the Big Island, as well as for the north facing shores of Niihau, until 6 p.m. today.

A long north-northeast swell is expected to build through the morning, peak at 12 to 16 feet this afternoon and diminish slowly through the weekend, according to the National Weather Service. Expect strong breaking waves, shore break and rip currents, making swimming difficult and dangerous.

A small craft advisory is also in effect until 6 p.m. tomorrow.