Coast Guard Helps Reposition Weather Buoy

 by Ens. Jeff West

HONOLULU — A U.S. Coast Guard cutter and crew recently helped the National Weather Service (NWS) restore a critical tool used to forecast incoming surf and weather around the Hawaiian Islands.

The Coast Guard Cutter Kukui, home ported in Honolulu, recently re-positioned NOAA Weather Buoy 51003 on scene about 205 nautical miles southwest of Oahu. The buoy was adrift for months after breaking free from its mooring in January. The Kukui’s crew put it back on station late last month after repairs were made in Honolulu.

“Buoy 51003 is in a strategic location for swells originating in the southern hemisphere near New Zealand and from typhoon generated swells in the Western Pacific,” said NWS Honolulu Forecaster Ray Tanabe, who often works with Coast Guard cutters such as the Kukui on these misions. “Data from buoys such as 51003 feed directly into numerical forecast models, and are critical because they provide surface data over the open ocean, where such data is extremely limited.”

The 6-meter long, 5.7-ton aluminum hull NOMAD buoy is operated by the National Data Buoy Center, a division of the National Oceanic and Atmospheric Administration (NOAA). For almost an entire day, Kukui and her crew worked in arduous conditions to anchor Buoy 51003 to the sea floor with a 6,000 pound anchor and steel chain. The buoy is attached to the ocean floor with a synthetic mooring line more than 20,000 feet long.

The sophisticated weather instruments housed on Buoy 51003 measure typical readings like temperature, pressure, and wind. However, it is also equipped with specialized sensors that calculate swell height, period, and direction. This data is used by the Honolulu NWS office to issue life-saving high surf advisories, analyze tropical cyclone formations, and fine-tune daily weather forecasts.

“We use buoy data to determine whether an incoming swell is higher, lower, or on par with what the swell models have been implying,” said Tanabe. “This comparison allows the NWS to adjust our forecasts if needed before the swell actually reaches the islands.”

The chain of four NOAA weather buoys which encircle the Main Hawaiian Islands are well known to local wave riders, who have come to rely on them to determine where and when the next big swell will break.

“My friends trip out when I tell them we’re working on the NOAA buoys,” said Petty Officer 3rd Class Seth Bumanglag, a Kukui crew member and avid surfer originally from Waipahu on the island of Oahu. “My friends would always use the NOAA buoys to tell how big the surf was going to be and where it would be good. I still don’t know how to read them, but now I’ve touched one and know how they’re anchored to the bottom.”

The Kukui is a black-hulled, 225-foot Juniper Class buoy tender home ported in Honolulu. In addition to servicing aids to navigation throughout the main Hawaiian islands and western Pacific ocean, the buoy tender and her crew of 47 also serve on law enforcement, marine pollution response and search and rescue missions.

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