I_G0ESHARD wrote:There’s one in the base game. You get it from the quest Treasure Island. I don’t know how to open it though.
The Pirate's Chest in the base game can be opened at the keysmith's shop in Mithria by talking to him and paying 300 gold, iirc. I'm not sure if the one from Celtic Queen can be opened in the same place, but I kinda doubt it. If there's a keysmith in Celtic Queen it might be worth checking there-- unfortunately I haven't got there yet myself so I don't have any better suggestions for that one.