In practice, the training is excellent and you'll have dozens of zero-visibility experiences before finishing the certification. You learn that as long as you h

In practice, the training is excellent and you'll have dozens of zero-visibility experiences before finishing the certification. You learn that as long as you have the line in your hand and you stuck to your gas limits, you have everything you need to make it out alive, even if it takes you twice as long to do so. ...the trick is what happens when you don't have the guideline in your hand, or something goes wrong with your equipment, or someone's tanks run out, or a diver gets lost, etc. But you train for that, too.