What is this strange metal artifact that washed up in North Carolina?

A mysterious metal object washed up on a beach in Corolla on the Outer Banks in North Carolina and nobody seems to know its origin. Is it part of a Russian nuclear sub? An ocean buoy? Advanced alien technology? Or something far stranger? From the Charlotte Observer:

Cape Hatteras National Seashore, which controls much of the land along the Outer Banks, says the object is outside its jurisdiction. "I don't know what the object is," said Mike Barber, a spokesman for the National Park Service.

Sam Walker, news director at Max Radio of the Carolinas in Nags Head, is the one who first started asking questions about the object. He says it's sitting far from any beach access ramp, making it tough for heavy equipment to remove it. "Stuff washes up all the time, and if it's not bothering anything, it just stays," he told the Observer. "There's no telling how deep this thing is in the sand."