Double Shot is the 2nd upgrade on the top path for the Monkey Buccaneer in BTD6. It makes the Monkey Buccaneer's main cannon fire two darts side by side every shot. This does not affect Grape Shot or Hot Shot. It costs $425 on Easy, $500 on Medium, $540 on Hard, and $600 on Impoppable.
Strategies
Due to the fact that this upgrade indirectly increases pierce and damage, positioning is important, long straight are ideal for this tower. This is especially so when upgrading to Destroyer.
Trivia
This is the only Buccaneer upgrade to share names with an already existing upgrade (shared by Ninja Monkey's Double Shot), since Buccaneer's Hot Shot upgrade name is only slightly different from Tack Shooter's Hot Shots upgrade.
This upgrade turns the Buccaneer's wooden boat hull into a steel boat hull.