Mine Menace Achievement in Skylanders Giants
Chapter 10 - Shoot down 10 mines
How to unlock Mine Menace
While defending the Dread-Yacht from attackers, you'll jump into the ship's turret. While in the turret, you'll be given various tasks to complete, one of them being "Clear the Mines." After completing that objective, just shoot down seven more. Basically, shoot everything that comes on screen, and you'll easily get this.