So how do you know if you're good, or if you're just overconfident?
I believe there are two aspects to this issue of "readiness", one physical and one mental. The physical aspects are pretty easy to judge. Somebody mentioned these already, but I would say that
at a minimum, a diver should be able to:
- Hover motionless for some extended period of time in good horizontal trim (no hand finning)
- Perform skills (mask removal, etc) while maintaining horizontal trim and vertical position in the water column
- Make a controlled ascent from 20-30 feet while maintaining horizontal trim
If you cannot do these relatively consistently, then I don't think you are ready for Cavern or Cave training (this from the guy who failed his Cavern class
).
Too many divers think they have good skills, but as soon as you give them something to do, or put something in their hands, they "lose it". Hand finning for stability is the worst sin, IMO (and also probably the hardest to overcome). When you are in an overhead, you are constantly using your hands for things (running the reel, controlling your light, etc), so that is a habit that needs to be broken early.
The issue of mental readiness is much harder to assess, and I don't know if I can offer any advice on that. It's hard to get inside someone's head to find out what is motivating them, and whether they are mentally prepared for the challenges of overhead environments. Some folks get into it because they are truly interested in learning about and exploring a new world of diving, while others are more into the macho "image" of being a Cave diver. Either way, it is not an activity to be undertaken lightly.