A message in a bottle can be found floating in the sea near the docks on the south-eastern pier on Whale's Maw, west of The Whaler. It can be investigated to receive a treasure map, which leads players to The Goon Docks.
This message in a bottle is currently visible. (wrong?) Once a message in a bottle is found and when a player has walked near its spawn location when it was visible it will always be visible, unless the message in the bottle or its treasure map is in the player's bank or inventory.