Captain's Chest
Captain's Chest is an object found in the Lost Rigger Cove subzone of Tanaris[76, 45], and requires the 
[Captain's Key] to open. The key is sometimes found inside a 
[Pirate's Footlocker], which occasionally drop off of Southsea Pirates.
Notes[]
The chest is found on the left pirate ship at Lost Rigger Cove in Tanaris. Go down a set of stairs to the stern cabin of the ship behind the swashbucklers.
Despite its name, this object is not related to the quest 
[10-30] The Captain's Chest.