Over 108 years ago, George P. Bidder III cast more than 1,000 messages in bottles into the North Sea, off Britain’s eastern coast. 

His goal was to track ocean currents, and, amazingly, his experiment sort of worked: around 55 percent of the messages were eventually returned to Bidder, a member of Britain’s Marine Biological Association. 

Some ended up on the shores of continental Europe, while others ended up closer to home. 

Bidder died in 1954, but the return rate for his letters ticked up a notch early last year, when a woman walking on a beach on the North Frisian Islands near the German border with Denmark discovered a Bidder bottle. 

The finder, a retired German postal worker named Marianne Winkler, promptly returned it to the Marine Biological Association, which also gave her the reward: one shilling, or about 17 American cents. 

“We found an old shilling, I think we got it on eBay,” Guy Baker, a spokesman for the association, told the Guardian. ”We sent it to her with a letter saying thank you.”

Guinness World Records has since verified the claim of it being the oldest message in a bottle ever found. 

“It is not known how Marianne plans to spend her shilling,” the organization remarks.