Planning for unreliable alternative exits is one of the fun aspects of cave diving: you virtually always exit by returning to your point of entrance, even if yo

Planning for unreliable alternative exits is one of the fun aspects of cave diving: you virtually always exit by returning to your point of entrance, even if you're nominally closer to another means of egress, since you can't be certain that the "closer" exit is genuinely navigable. When diving a traverse between two points, the best practice involves diving as far as you can one way, leaving a marker, then entering from the other side on a second dive, evaluating your gas situation at the marker, and then either continuing or aborting the dive.