The Easy Way to Know the Height of the Cliff You're Jumping Off

So you fancy yourself a pretty good cliff-jumper. You always personally inspect your landing spot for hazards and the necessary depth. Good. But here's the thing, how do you know how much depth you need unless you know exactly how high you're jumping from? With NASA smarts, that's how. » 8/05/14 12:14pm 8/05/14 12:14pm