Doubloon

"This is a doubloon. They are the only currency accepted in Jolly Roger's Lagoon."

- Jamjars

Doubloons are the only accepted form of currency of Jolly Roger's Lagoon, and only appear in Banjo-Tooie.

Doubloons can be spent at Jolly Roger's Tavern, Pawno's Emporium, and Captain Blubber's Waveracer Hire. In total, there are 30 doubloons scattered across the lagoon, and most are either out in the open or can be uncovered by using the Bill Drill.

Captain Blackeye will give Banjo and Kazooie two gold doubloons for a glass of water, but these cannot actually be used to buy him a drink and are simply extra tokens. Talk to him multiple times to obtain these doubloons.

To complete the lagoon's challenges, at least 26 doubloons must be spent; 20 for Pawno's Jiggy, 5 for his Cheato Page, and one for a box of Turbo Trainers from Captain Blubber, which is required to collect one of the level's Jinjos.

Two doubloons can be used to rent the room in Jolly's Tavern which has one of Jamjars' silos in which Banjo and Kazooie can learn the move Sub-Aqua Egg Aiming. Currently, the two remaining doubloons have no known use in the game.

Trivia

 * Collecting all 30 doubloons in Jolly Roger's Lagoon unlocks a special gamer picture in the Xbox Live Arcade version of the game.
 * Although it is said that that Doubloons are the only accepted form of currency of Jolly Roger's Lagoon, the menu in Jolly's Tavern shows items priced using dollars. However, this could just mean that the same symbol ($) happens to be used for Doubloons in the Banjo-Kazooie Universe.