All the way from the USA.

I found this washed up on the shore near Clifden, Co Galway. It has a reg no on it. I contacted the maine lobster association as I guessed it may have come from around there. They were able to tell me that it had come from a fishing vessel from Vinalhaven, Maine. I googled it, it looks like nice picturesque place. I wrote the to the owner of the buoy and informed him where I found it and if he wants its back I arrange shipping  :-). It is currently on display in a fish shop in Clifden.
Another interesting point about the buoy is that it has a "whale swivel" attached. It is the black swivel attached to the bottom. You can see a portion of the swivel has a reduced diameter. This is a deliberate weak spot in the swivel which will break the rope coming from the traps to the buoy if it gets caught in a whales fin.