Beyond the Horizon: the Drifter that Returned from Sea

In August 2024, as science teacher Tonya Prentice planned her travel to NOAA Ship Henry B. Bigelow, she made sure to pack stickers. Some stickers were from Tremont Consolidated School (mascot: Wildcats), where she teaches middle school students on the southern shore of Maine's Mount Desert Island. Other stickers were from NOAA's Teacher at Sea Program , through which she would spend the next 2 weeks at sea.

Tonya boarded the Bigelow in Newport, Rhode Island, joining a team of NOAA scientists to conduct an ecosystem monitoring survey of the Northeastern U.S. shelf. The ship transited to sampling stations from the New York/New Jersey Bight to the Gulf of Maine-as far north as Tonya's own island. And in between measuring water quality, collecting plankton, and observing marine life, Tonya used her stickers to decorate two drifting buoys.

With help from the scientists, Tonya tossed the drifting buoys (or "drifters") over the railing of the ship at two different locations near the edge of the continental shelf. She dropped one offshore from Nantucket, and the other south of Long Island. Once at sea, each drifter's folded-up " drogue " (which looks like a fabric tail) expanded and extended down into the water column, anchoring the drifter to the near-surface current. The drifter then began transmitting its location and measurements via satellite hourly.

Back at school in Maine, Tonya and her students tracked the drifters' progress throughout the following school year. They plotted the coordinates and worked to connect the observation data to global environmental patterns. "This interactive project brings abstract science concepts into a tangible experience," Tonya explains, "encouraging inquiry, problem-solving, and environmental stewardship."

Initially, both of Tonya's drifters drifted west and south toward the mainland. But then one drifter caught the Gulf Stream and looped its way east, far into the middle of the Atlantic Ocean. Last we checked (December 2, 2025), it is visiting the Azore Islands, continuing to transmit sea surface temperature data after more than 15 months at sea!

The second drifter's ocean adventure came to an earlier end. In January, as it approached the coast of Delaware, its drogue detached and the drifter ran aground, ending the accuracy of its oceanic measurements. It finally stopped transmitting altogether in late April near Ocean City, Maryland.

When the "dead" drifter washed back toward an inhabited shoreline, Tonya's stickers provided passersby with clues to its identity. In mid-May, a music festival-goer spotted the drifter and shared a photo of it with the Teacher at Sea program's Facebook account. Later that month, the drifter washed up to the private dock of Berlin, Maryland resident George Berrue. He spied the Tremont Consolidated School stickers and called the school to let them know he had found the drifter. Would they like to have it back?

Getting the recovered drifter from Maryland to Maine took months of coordination. The buoy portion was quite heavy-more than 50 lbs-and after months at sea it was covered in barnacles. In August, George fished the buoy out of the water, cleaned it up, and drove it to NOAA's Cooperative Oxford Lab in Oxford, Maryland. The drifter spent a couple weeks at the lab's Environmental Science Training Center drying out and getting prepped for the travel up to Tonya in Maine.

By the time it arrived in Maine in late September, tracked by FedEx instead of satellite, the drifting buoy had undergone almost as much of a journey on land as it had by sea.

"I have it in my classroom with a map of where it traveled and the data it collected," says Tonya. "My students were very excited to see it!"

The drifter's data is not only for the benefit of Tonya's classroom. NOAA's Global Ocean Monitoring and Observing Program deploys these drifters around the world to measure sea surface temperature and other ocean variables over time. The observations collected by Tonya's drifters, and the more than 1,100 drifters currently bobbing around the world's seas, are crucial to scientists' understanding of weather and ocean circulation . The drifters' data inform hurricane forecasts, help predict the movement of larval fish and marine debris, and reveal important ocean trends.

Through NOAA's Adopt-a-Drifter Program , educators from all over the country can apply to adopt and track these drifters with their schools. But a Teacher at Sea has a unique opportunity to deploy the drifters from the ship personally. "I was so thrilled to learn that Tremont Consolidated School had been given two drifting buoys, allowing our students to participate in a cutting-edge, real-world scientific endeavor," Tonya recalled in her blog .

Since 2003, more than 40 Teachers at Sea have deployed drifting buoys through partnerships between the two programs. But Tonya's experience is unique still. Thanks to a lucky trajectory, helpful members of the public, and Tonya's stickers, this is the first time that an adopted drifter has ever followed the teacher home.

NOAA's Teacher at Sea Program would like to thank Erik Weber, who first reported spotting the drifter during the Boardwalk Rock festival in Ocean City; George Berrue, for retrieving the drifter, cleaning it, and driving it all the way to Oxford; and Bart Merrick, NOAA Chesapeake Bay Education Coordinator, for helping TAS Program Coordinator Emily Susko transport the heavy drifter to a shipping location.