A message in a bottle cast out to sea off the coast of Maine in 1998 was found earlier this month on a Scottish island — completing an epic 21-year, 3,000-mile journey, according to reports.

Matt Rhoades was just 13 years old when he delivered the message while vacationing with his family in Well, Maine.

The youngster’s simple message read: “Hello, my name is Matt Rhoades. Please write back,” along with his then-New Hampshire address, according to the Gloucester Daily Times.

Rhoades, now a 34-year-old musician living in Newburyport, Massachusetts, was contacted on Twitter earlier this month by Scotland native Mike Bolam, who said he found Rhoades’ long-lost letter during a family trip to the Scottish island of North Uist.

Rhodes at first believed Bolam’s message “was spam,” he told the paper.

But once he saw the photo of the letter, adorned with his adolescent handwriting, he realized it wasn’t a hoax, according to WHDH.

“There’s my handwriting, everything. All the info. Everything accurate — and I was like, ‘Holy crap, I remember doing this,’” he told the network.

“I mean honestly, I probably forgot about it like an hour after I did it. I was like a little kid, and just thinking ‘this is so magical.’ ”

Ruminating over his message’s unlikely discovery, Rhoades has one regret.

“That thing has been floating for most of my life,” he told the Gloucester Daily Times. “Had I known it would be found 20 years later, I would have written something much more substantial.”

There appears to be one more chapter in the message in a bottle’s journey, as Rhoades told WHDH that he wants to fly to Scotland to see the letter and meet the message’s receiver.