On February 27, 2025, the Royal Canadian Navy’s HMCS Margaret Brooke crossed a symbolic threshold—the 60th parallel, marking the boundary of Antarctica—while supporting Canadian scientists in a vital scientific mission. Amid the choppy waters of the Drake Passage, the ship’s science team launched an Argo float probe, a sophisticated tool designed to measure ocean conditions, as part of Operation PROJECTION 2025. This historic voyage, the first by a Canadian naval vessel into Antarctic waters, underscores Canada’s growing role in polar research and climate science.
HMCS Margaret Brooke, a Harry DeWolf-class Arctic and Offshore Patrol Vessel, set sail from Halifax on January 10, 2025, bound for South America and Antarctica. After embarking 15 Canadian scientists from Punta Arenas, Chile, on February 23, the ship ventured into the Southern Ocean, led by Chief Scientist Dr. Thomas James of Natural Resources Canada. While the broader mission focuses on climate change, ocean currents, and environmental pollutants around the South Shetland Islands and the Antarctic Peninsula, the launch of the Argo float stands out as a key contribution from Fisheries and Oceans Canada.
As CBC News reported from aboard the ship, the science team deployed the Argo float on February 27, just as the vessel crossed the 60th parallel. “This is the float that we’re going to launch today—it’s an Argo float,” explained Sofia Johannesson of Fisheries and Oceans Canada in an interview with CBC’s Susan Ormiston. She described its components: “This is the antenna that it uses to talk to the satellite, and this is the instrument package in here—it measures the temperature and salinity of the seawater.” Once released overboard, the float begins a remarkable journey. “As soon as we let it go, it will go down to 1,000 meters and then float along at 1,000 meters wherever the current takes it for about 10 days,” Johannesson noted. “At the end of 10 days, it will go down further to 2,000 meters and then shoot right up to the surface,” where it connects with GPS satellites to pinpoint its location and transmit stored data.
This Argo float, expected to operate for three to five years, joins a global network of approximately 3,000 such devices. “The Argo float array goes all around the world in all the oceans—not so many in the Southern Ocean as everywhere else,” Johannesson said, highlighting the region’s relative underrepresentation in this critical data collection effort. By measuring temperature and salinity, these floats provide insights into how oceans are warming, feeding into climate models that improve short-term weather forecasts and predict long-term climate change. In the Southern Ocean, the Antarctic Circumpolar Current—an unimpeded flow encircling the continent—carries these floats, offering a unique window into this vital regulator of global climate systems.
The conditions aboard HMCS Margaret Brooke reflect the ship’s approach to Antarctica’s frontier. “For much of the trip, it’s been sort of light rain and relatively warm,” reported Susan Ormiston, “but we’re noticing a discernible drop in temperature as we move into Antarctica, where the cold Southern waters meet the Atlantic, which is a bit warmer.” The crew anticipates snow by the evening of February 27, with landfall on the Antarctic Peninsula expected by late Friday or early Saturday—still more than a day away from the float’s launch site. This transition into colder, harsher weather mirrors the ship’s shift from naval operations to a platform for cutting-edge science.
The Argo float deployment is just one part of a packed research agenda. Scientists are also sampling water for contaminants like mercury and microplastics, studying glacial retreat, and examining species distribution—data with global implications. Supported by Polar Knowledge Canada, the Marine Environmental Observation, Prediction and Response Network (MEOPAR), and a partnership with Chile’s Instituto Antártico Chileno, the mission exemplifies collaboration across borders and disciplines. Rear-Admiral Josée Kurtz, Commander of Maritime Forces Atlantic, called it a “historic moment” for Canada’s navy, while Commander Teri Share, the ship’s commanding officer, expressed the crew’s pride in this rare scientific endeavor.
Commissioned in October 2022, HMCS Margaret Brooke has already tackled diverse missions, from hurricane relief to drug interdiction. Its Antarctic journey, set to conclude in May 2025 with its return to Halifax, adds a new dimension to its legacy. For Fisheries and Oceans Canada, the Argo float’s data will enhance understanding of the Southern Ocean’s role in climate dynamics, potentially revealing parallels with Canada’s Arctic waters. As the ship presses deeper into Antarctic territory, it’s not just breaking new ground for the Royal Canadian Navy—it’s helping map the future of our planet’s oceans.