The City and County of Honolulu Ocean Safety Division has replaced two lifeguard towers at critical beaches on Oahu’s West and North shores ahead of a large northwest swell that was predicted to strike Tuesday evening, peaking today at 15 to 25 feet with 20- to 40-foot faces.

The swell kicked off the winter’s big-wave season in Hawaii, when dangerous waves and currents — combined with holiday crowds — keep lifeguards on overdrive.

On Monday, Ocean Safety replaced the lifeguard tower at Ehukai Beach Park, from which lifeguards survey a swath of North Shore breaks including the Banzai Pipeline, and on Tuesday the division installed a new lifeguard tower at Depot Beach Park in Nanakuli. The two new towers are made of white fiberglass, a material introduced on Oahu’s beaches in the early 2000s, replacing the classic orange wood structures. The old Ehukai tower dated to 2003.

While the fiberglass towers, built in San Clemente, Calif., are highly durable and built for employee safety and maximum visibility, over time they can start to leak, weaken or delaminate. The new replacement towers now feature a reinforced deck designed for Hawaii’s high wind and high surf, more secure flaps, hardware to lock the towers, and tinted windows to reduce glare, according to an Ocean Safety news release Tuesday. Ocean Safety is in the midst of a multiyear plan to replace all its 41 towers, seven of which were replaced in the last year.

The Ehukai replacement was especially timely, as “the surf really picked up towards the late afternoon on the north shore,” EMS spokeswoman Shayne Enright said in an email late Tuesday, after North Shore lifeguards had taken roughly 350 preventive actions and conducted 19 rescues using watercraft (Jet Skis), staying on the beach past 5:30 p.m. “to make sure everyone got in safely.”

The tower replacement project comes as Ocean Safety readies for “dawn to dusk” operations, Ocean Safety said, for the reason that lifeguards generally start at 9 a.m. and close the tower at 5:30 p.m., but many calls for help come before and after those hours.

A “dawn to dusk” lifeguard program will ensure that a mobile unit nearby can respond, Ocean Safety Chief John Titchen said in a statement, expressing his appreciation for an initiative that Mayor Kirk Caldwell signed into law in November 2019 which requires that Ocean Safety in July begin a program to eventually provide extended-hours coverage for Oahu.

Titchen thanked Caldwell for adding 23 full-time positions to Ocean Safety in this year’s budget, hires that will form the backbone of the initial phase of Ocean Safety’s “dawn to dusk” program. The division currently has 212 full-time and 28 contract positions.

“We are working closely with the Budget and Fiscal Services and Human Resources Departments in high hopes that we will be able to fill those positions in time to start a program for extended coverage early next summer,” Titchen said.

“I could not be prouder of the outstanding work of our lifeguards, particularly during the (city’s) response to COVID,” Caldwell said in the release. “When we closed beach parks, Ocean Safety figured it out and went to mobile operations from dawn to dusk.”

Ocean Safety received capital improvement projects funds for the multiyear tower replacement project, which was put out for bid, and entered into a master agreement with Nakasato LLC.

To expand its reach beyond the 41 towers — placed at strategic beach locations on the South Shore, Windward side, North Shore, Leeward Coast and at Hanauma Bay — Ocean Safety also relies heavily upon mobile units, including trucks, all-terrain vehicles, utility terrain vehicles and one 21-foot boat, the release said.

“On behalf of all our lifeguards, Ocean Safety wants to thank Mayor Caldwell and his Administration for its outstanding support of our organization,” Titchen said. “We also really want to thank the public we serve.”

The division asked that people call 911 if they see someone in trouble and are not near a manned lifeguard tower.