This might be a better question for the hard pushing sump divers but, generally speaking, what can be expected at the bottom of a 25+ foot deep lake that drops below an otherwise flat, level stream passage cave?
In other words, I'm caving along in a cave with over a mile of generally flat, stream passage. All of a sudden the bottom drops out and plunges 25+ feet in a deep lake. I've seen it several times and always wondered what is down there. Is this a good place to look for more passage or do they usually peter out? Any ideas what causes this?