Your ball has come to rest in the sand near the edge of the hazard and you have to stand outside the bunker to take a proper address. Not only that, the ball is so far below your feet you're in danger of splitting your khakis right where the sun don't shine when you try to bend down to the ball.
You may have never thought to take a swipe from your knees, but dropping down to this stance gives you plenty of room to swing your arms through the hitting zone always a must. It also provides you with a solid base from which to move the club back and through as well as the ability to set the club at its natural lie angle or as close to it as possible. The only penalty is an extra trip to the dry cleaners.
BLAST FROM YOUR KNEES
Your knees and shins give you plenty of ground support, so don't be afraid to make an aggressive swing (flare both feet out for an even wider base). Keep your rear end and your back straight, and try to hold this position as you swing the club back and through. Don't pick the club up get your shoulders moving as well as your arms.
The biggest mistake you can make is bending over too much. That makes it easy to lose your balance. Use your butt as ballast to keep your posture tall and your swing in control.