[T.B. Yoits]

That bottle travelled much farther than 4,600 miles unless it came through the Panama Canal, which I doubt. It had to come through the Strait of Magellan or across the arctic.

The bottle most likely got picked up in the ballast water of a ship in Hawaii and dumped into the water in Florida when the ship put in a port call. Neither the glass nor the paper look like they've been exposed to 8 years of sunlight so it's likely been sitting in the ship's ballast tank the whole time.

From Wikipedia:"Cruise ships, large tankers, and bulk cargo carriers use a tremendous amount of ballast water, which is often taken on in the coastal waters in one region after ships discharge wastewater or unload cargo, and discharged at the next port of call, wherever more cargo is loaded."

[HartleyMBaldwin]

it's likely been sitting in the ship's ballast tank the whole time

That's not impossible, but I think there's a much greater probability that someone would post a made-up story on the internet. With photos, even.