You draw the line to where someone who meets the lowest of the standards shouldn't go beyond. On a case by case, I think there's some wiggle room.
I think as long as you follow the 4 rules (excluding training), and consider your experience in the type of cave that you're diving, you'll be fine. I think training is important because it teaches you what you don't know, but after basic cave, if your instructor did his job, you *should* be able to evaluate a dive and determine if you need additional instruction.
Case in point...I have a full cave card, so I can basically do whatever dive I choose. Either my buddy or myself have turned 3 dives recently because we had reached the limit of our comfort level. IMO that's what training should do, let you know when you need a) more experience, or b) more training, and leave those dives for a later day.
I know it's a pathetic hypothetical example on my part, but 1/6ths on AL80's in mexico can get you further than 1/3rds in Ginnie in Florida. So by following standards, you can go further in silty no flow cave than in high flow cave that's near impossible to silt. That's kinda my whole point, you have to keep in mind WHY the standards are there.
I don't see an issue with a basic diver with 50 post basic dives diving 1/3rds in a high flow system, I see a huge issue with a basic diver using cave filled LP120's to 1/6ths in a shallow MX system. The wiggle room goes both ways.
I agree with wiggle room. I dont think that doing jumps and 1/3's on a basic cave cert is wiggle room, it sounds like cave2/full cave to me.
I also see a huge issue with a basic diver doing 1/6ths in a no-flow cave in mexico, and yes, thats "common sense" in that while it may not be explicitly "forbidden" it is not really within the spirit of the standards.
If a diver with 50 dives thinks they are OK diving 1/3's then why not find out and go get the formal training rather than give itg a go and see what happens (and hope their mentor covered the cases when it's especially unsafe to go to 1/3's)
Yes, there cannot be a cert card for everything or else the WKPP or EKPP or many other groups exploring would be SOL
And I agree with your POV on training. I have GUE cave2 and I have turned a bunch of dives for similar reasons....
I also agree that if you have full cave, it's possible with a good mentor to do single-stage dives safely (if you have a good mentor) but you well know that when that topic came up on another board, there were some very (at at least to me) issues from multiple experienced divers on how to dive stages....
For me, it seems pretty clear. Yes, some people may be able to pick this stuff up better than others, but yes training does give a basic minimum standard (in the ideal case I guess), whereas a mentor doesn't really have any standards or anything behind what they are saying.
Just because I am trained to use a stage in a dive doesn't mean I can train someone else how to do it ...
People who want to significantly exceed their training I suppose will always exist, and some may well even scoff at the need for formal training.