Let’s say, for whatever reason, you’re forced to set up your tent on solid rock, essentially making your plastic or metal tent pegs useless. You still have two options for anchoring your tent’s pegging points and guy lines, however: either use the deadweight of surrounding rocks or drive specialized rock-climbing anchors, known as chocks, into natural crevices in the rocky terrain.
Secure a three- to four-foot piece of parachute cord around a small, irregularly shaped rock; do not use a round rock because the line will only slip off. Tie the opposite end of the cord to one of the loops in the tent floor where you would normally insert a tent peg. Now weigh down the small rock with bigger, randomly shaped rocks until you feel the hold is secure. Repeat for all pegging points, typically four.
Next, attach the fly as you normally would, then work on securing the guy lines. To do this, tie the loop on the guy line to a length of parachute cord, then anchor the end of the cord to a rock pile, as outlined above. This way, you avoid chafing the guy lines, which are typically too short anyway for this technique.
When the wind is extreme, rocks might not cut it, so you’ll want to use a chock. Also referred to as a nut, a chock is a metal wedge threaded on a wire that’s driven into cracks for safety and support. You can tie your tent’s pegging points and guy lines to the loop in the chock. They’re reusable and quite economical, but you really only need them in extremely windy situations.