It was Thanksgiving Day, 1968. Richard Nixon had just been elected President of the United States. "Hey Jude" began spinning on record players in living rooms across America. And it had been the deadliest year of the Vietnam war for the U.S. since the conflict began 13 years earlier.
As families and friends gathered for their holiday feasts and took a beat from the "year that shattered America," a U.S. Coast Guard airplane flying due east of Daytona Beach, Florida dropped five glass bottles into the open ocean.
What must have looked like a heinous act of littering from the sky was actually part of a study led by WHOI physical oceanographer Dean "Bump" Bumpus to measure ocean currents in the North Atlantic. Between 1956 and 1972, some 300,000 bottles were released into the ocean by ships and planes, along with more than 75,000 seabed drifters.
"It was an amazing project in terms of how many bottles and drifters were put in the ocean," says WHOI physical oceanographer Pelle Robbins. "Bump really marshaled the forces from both planes and ships to make it happen. It was very inspirational and got a lot of people back then thinking about ocean circulation."
This past April, one of the bottles dropped offshore of Daytona, No. #71645, was found washed up on Hendrick's Head Beach in Southport Island, Maine. Charlie Britton, a retired educator and Southport native, had been picking up trash from the beach after a bad winter storm had barreled through.
"I looked down and saw this bottle staring at me," says Britton. A note inside had a bold inscription at the top: BREAK THIS BOTTLE.
A real message in a bottle, Britton thought. He first tried removing the bottle's rubber stopper, but it wouldn't budge. So, he tapped the bottle onto a nearby rock to break the glass, pulled the letter out, and started reading.
The letter was from Woods Hole Oceanographic Institution and provided a brief explanation of the ocean current/drift study. And, it promised a 50-cent bounty—enough to buy two cheeseburgers and a Coke at McDonalds in 1968—to whoever sent back the return card with details about when and where the bottle had been found.
"Your giving accurate information will be of great aid," the note read.
Bump's idea of setting glass bottles adrift to track ocean currents may have been resourceful, but it wasn't new. Ancient Greek scientists are said to have used drift bottles to measure currents in the Mediterranean Sea—possibly as early as 310 B.C—and that Albert I, Prince of Monaco, used them in the late 1800s and early 1900s to investigate the dynamics of the Gulf Stream as it approached Europe.
The method wasn't nearly as accurate or efficient as today's GPS-enabled surface drifters and fixed current sensors, but the WHOI drift bottle program yielded about a 10 percent return rate—roughly 30,000 "Point A to Point B" drift paths. Robbins acknowledges that it was a decent-sized data set for the time: "Back then, they didn't have anything else [to collect the data]," she says.
It was also an expensive data set, at least by today's standards. These days, physical oceanographers often collect not thousands—but millions—of current measurements over the course of a research project. That would make the 50-cent per measurement bounty unrealistic today, at least from a cost standpoint.
The fact that a drift bottle couldn't report anything about how, and when, it got to its destination made it difficult to interpret the data. But according to the U.S. Navy, the combination of drift bottles and seabed drifters ultimately "provided invaluable information of surface and bottom circulation along the continental shelf of eastern North America."
How long did it take for Bottle No. #71645 to make the 1500-mile (2400-kilometer) journey from Daytona Beach to Southport, Maine? It's anyone's guess. When Britton found it, the bottle was in pristine condition with no biofouling or debris caked on it, which suggests it had been beached there for a while. But whether it got there within days of Thanksgiving, 1968, or much more recently, we'll never know.
To Britton, it makes no difference—he was just happy to have stumbled upon a piece of oceanographic history (and WHOI did send him fifty cents).
"For the bottle to have lasted all this time is really interesting," he says. "It gave this 61-year-old retired guy a thrill."
