By ENS Cullen Hauck
NOAA Ship Fairweather went farther north than ever before for the U.S. Coast Guard’s Port Access Route Study, a multi-year effort to establish new maritime traffic routes, safety zones, and use areas in the U.S. Arctic waters.
In 2025, Fairweather conducted a survey of over 5,500 linear nautical miles to provide valuable environmental information in support of the U.S. Coast Guard’s Arctic Port Access Route Study (PARS), a multi-year effort to establish new maritime traffic routes, safety zones, and use areas in the U.S. Arctic waters. Required by the Ports and Waterways Safety Act, PARS aims to increase traffic efficiency and minimize the risk of marine casualties by analyzing vessel traffic movement and the needs of waterway users. A critical step in establishing new traffic routes is ensuring the proposed traffic lane is safe for navigation, with updated bathymetric data and nautical charts.
The Northwest Passage, which crosses through Arctic waters, has historically gathered interest as a traffic route. This passage over Alaska’s northern shore to the Canadian Arctic Archipelago was sought as a shorter alternative for traversing between the north Atlantic and Pacific oceans (potentially shaving a week or more of transit time when compared to passing through the Panama Canal). The passage is challenging, if not impossible, to navigate due to year-round sea ice coverage, inconsistent patterns of summer ice melt, and sparse modern bathymetric data.
Recent significant changes in sea ice conditions and ship traffic have created renewed interest in designating an official route in the U.S. Arctic. The extent, or coverage, of sea ice in the Arctic has reached record lows (the 2024 NOAA Arctic Report Card noted all 18 of the least September minimum ice extents have occurred in the last 18 years). Moreover, a steady warming pattern has been observed in the ice-free regions since 1982. These longer ice-free periods have impacted communities and ecosystems in these northern latitudes–increasing the area’s capacity for trade, science, natural resource exploration, and tourism. The U.S. Coast Guard cites the potential for alternative, faster commercial traffic routes in these remote waters as drivers for conducting the study.
While passing northbound through the Bering Strait, crewmembers got a rare sight of the Diomede Islands–the closest point between U.S. and Russian territory, with a separation of a mere 2.8 miles between Big Diomede (Russia) and Little Diomede (U.S.). The crew waved to tomorrow from today as the international dateline divides the two islands.
During the survey, which took place from July through September of 2025, Fairweather’s crew experienced Arctic wonders from the surface of the water to the seafloor. In the Chukchi Sea, hydrographers standing watch noticed ice scours in the seabed generated by years of friction between floating sea ice and the sediments below. On occasion, crewmembers climbed to the flying bridge to observe flickering, green northern lights dazzling the night sky. Wildlife sightings were frequent, featuring walruses, sea lions, gray whales, fin whales, bowhead whales, and even a solitary, swimming polar bear.
Scenes from the Arctic: A polar bear, left, and the northern lights, right (ENS Kate Elmer/NOAA)
As the ice extent receded over the course of the summer, Fairweather pushed further into the Arctic, eventually steaming east of Utqiagvik, Alaska. There, in the Beaufort Sea, depths plummeted to several thousand meters, dwarfing the 50-meter depths of the Chukchi Sea to the west, which sits on a continental shelf. Though mostly clear of obstacles, the Beaufort Sea presented a final navigational challenge for Fairweather’s bridge crews, with deceptive chunks of sea ice often revealing themselves at close range and in poor visibility. In order to acquire seafloor data while prioritizing safety, the bridge teams occasionally had to deviate from course and maneuver the ship safely around sea ice. All in all, Fairweather spent a total of 586 hours actively acquiring data.
Observed sea ice, left, and ship track deviation, right (ENS Nick Edmundson/NOAA)
Fairweather’s bathymetric findings from the area will provide valuable environmental information for the development of a safe vessel passage that can accommodate future traffic in the region. Establishing safety fairways through the Arctic ensures that ships remain within surveyed waters to avoid running aground, and larger ships avoid scraping along the coast, potentially disturbing whaling areas and coastal communities. Once the U.S. Coast Guard’s review is complete, the new route will be presented to the International Maritime Organization for approval and inclusion in navigational charts.
To see full coverage of the PARS area and learn about NOAA’s additional Alaska seafloor mapping projects, check out Coast Survey’s ArcGIS StoryMap.