A lost buoy from Cape Breton has been found off the coast of Ireland.

The drifting beacon, known as the Orpheus Rock buoy, was originally moored near the Green Island lighthouse off the coast of Arichat.

After bobbing aimlessly across the Atlantic Ocean, the missing marker ended up in County Clare, Ireland, hauling 60 metres of chain it carried from Cape Breton.

"Once it's drifting off its position, obviously it becomes a danger rather than an aide to navigation," Robert McCabe, director of operations for the Commissioners of Irish Lights, told CBC's Information Morning Cape Breton on Wednesday.

McCabe estimated the metal buoy is five metres high and two metres in diameter. It weighs about three tonnes.

Lost buoys usually come from U.S.

He said buoys like this wash up in Ireland about every three or four years or so. These buoys are usually from the United States, where they get caught in the Gulf Stream.

When it happens, the Commissioners of Irish Lights — a maritime safety organization — recovers buoys at its own cost and offers to send them back where they came from at that country's cost.

The Commissioners of Irish Lights says a buoy usually washes up every few years, but it's usually from the U.S. (Irish Coast Guard, Kilkee Unit)

The buoys, however, usually become permanent residents of Ireland —their home countries aren't keen to have them back.

"It's never worthwhile shipping something as large as that and as damaged as that," McCabe said. "It's a fairly bare-looking structure at this stage."

When the Cape Breton buoy was discovered, Pat Flynn of the Clare Herald tracked it down to the Canadian Coast Guard, going off only the rusted-out inscription "NQ 1."

The coast guard, which confirmed the buoy is theirs, said the marker was last replaced in 2014, meaning it could've had a lonely, three-year float before being found.