My friend had taken another friend rappelling to an area a week before, and when he and I went he thought he remembered the right cliff face. We had a 300 foot rope that we doubled up to make two 150 foot runs, and as we started down he realized we weren't at the same place as he was a week before.
He asked me to wait while he went down the cliff a bit to find a place where we could swing over to, where our ropes would reach the bottom of the cliff face. I waited for several minutes while he searched and searched, but my brake hand started to tire and give out. My grip loosened, and I began to slide down the rope.
After several minutes he finally found a way off the cliff and I was able to move over. By the time I got there I had about a foot of rope left. Once we were off the ropes and away from the cliff a bit we could see that our ropes were short by more than 100 feet.