What makes one cave dive "bigger" than the other?

[boulderjohn]

Let me ask you what your initial hope was, simply due to the skiing and climbing analogies: Were you hoping for a scale for different passages/systems?

I had a number of ideas--I wanted to talk to experts for their ideas.

One idea would be to do something such as is used for river rafting/kayaking, where a river may have a number of ratings along the way, depending upon the strength of a rapid. that rating may change during the year as the water level changes. Similarly, a cave can change depending upon factors like visibility and flow.

 

[Bennno]

We need a NACD Cave rating commitee!

One idea would be to do something such as is used for river rafting/kayaking, where a river may have a number of ratings along the way, ...

Can you give an example of how this would help someone to plan a dive? If I knew a dive in Ginnie to 800' is a level 4 dive, what extra info is it giving me?
I sounds like you guys want a system just for the hell of it.

 

[PfcAJ]

We need a NACD Cave rating commitee!


Can you give an example of how this would help someone to plan a dive? If I knew a dive in Ginnie to 800' is a level 4 dive, what extra info is it giving me?
I sounds like you guys want a system just for the hell of it.

"Ginnie springs is rated a level 4 on a 1 to 10 scale, a relatively easy dive by cave diving standards. After last weekend's fatality, the 3rd this year at Ginnie alone, state legislators are considering a statewide ban on all cave diving activities to protect landowners from liability."

 

[tbone1004]

engineers my friend. It's not necessarily the cave, it could be a section of the cave, or it may not be the cave itself. Depths up to 100ft get a 1x adjustment, depths to 150, a 1.5, to 200, 2.0, etc etc. Penetration gets an adjustment per 1,000ft of penetration or some other arbitrary number, decompression obligation, navigational decisions etc. They all get added up and you can say a dive in Peacock as a dive factor of 1.0 if you are going up the gold line, but jumping into the crossover, then to the bypass, back to Olsen, then up the gold line has a factor of 2.0 because of the navigational complexity.
Don't grade the caves, grade the dives, that was the point of the OP. The cave itself is irrelevant, it's the dive plan

 

[Bennno]

engineers my friend. It's not necessarily the cave, it could be a section of the cave, or it may not be the cave itself. Depths up to 100ft get a 1x adjustment, depths to 150, a 1.5, to 200, 2.0, etc etc. Penetration gets an adjustment per 1,000ft of penetration or some other arbitrary number, decompression obligation, navigational decisions etc. They all get added up and you can say a dive in Peacock as a dive factor of 1.0 if you are going up the gold line, but jumping into the crossover, then to the bypass, back to Olsen, then up the gold line has a factor of 2.0 because of the navigational complexity.
Don't grade the caves, grade the dives, that was the point of the OP. The cave itself is irrelevant, it's the dive plan

It's not gonna help you plan anything.

I don't get it.

 

[boulderjohn]

Can you give an example of how this would help someone to plan a dive? If I knew a dive in Ginnie to 800' is a level 4 dive, what extra info is it giving me?
I sounds like you guys want a system just for the hell of it.

Yep, you are right--if you already know all there is to know about a cave, a rating system would not help. Similarly, I don't need street signs for the routes I drive regularly, so I guess we have no need for street signs.

Several years ago, I was diving with someone in a Yucatan cave. She was a dive guide who had never been in the section of cave we were about to visit. It had been explored and lined, but it was very rarely traveled. She, a petite sidemount diver, said she would travel well ahead of me, a much larger backmount diver, so that if she encountered a restriction she thought I could not handle, she could turn the dive in plenty of time. We had a successful dive, but she certainly had a much smaller version of me in her head than the reality, because I had some very, very tough squeezes. What if we had come to a restriction early in the dive that ether I or both of us could not have handled? the dive would have been disappointingly over very early.

Similarly, when I dived in the Bahamas with Brian Kakuk, I was also backmount, and he had the knowledge that kept me out of passages I could not have negotiated that way. What if I were in a situation where I had to make those decisions for myself?

Current cave maps outline the directions of caves with very rough indications of the size of passages. What would be wrong with adding a numeric code indicating things like sidemount-only restrictions? That way people who do not know the cave well or do not have access to people who know the cave well can have some indication as to whether or not they can handle it?

 

[Bennno]

Similarly, I don't need street signs for the routes I drive regularly, so I guess we have no need for street signs.

A street is nothing like an underwater cave.

What if we had come to a restriction early in the dive that ether I or both of us could not have handled? the dive would have been disappointingly over very early.

So the dive rating should also factor in how chubby someone is? ... If you can't fit through a restriction, too bad. Some maps already say when something is a SM section... so no rating needed.
What you are talking about is rating restrictions and peoples chubbyness, not dives.

What if I were in a situation where I had to make those decisions for myself?

Yeah, what if? What would happen?

 

[boulderjohn]

A street is nothing like an underwater cave.

It's called an analogy. Check the link for an explanation.

the point is that if you know a cave well, you would not need any sort of map or guide. If you don't know it well, such a map or guide would be useful.

 

[boulderjohn]

Yeah, what if? What would happen?

Well, I think that if I were a backmount diver and a code on a section of a map I was considering indicated it would be backmount only, then I would have second thoughts about going there.

I have done a number of dives in the Yucatan where no one in my group had ever done the dive before and a little more information would have been useful.

 

[Bennno]

It's called an analogy. Check the link for an explanation.

I know what an analogy is, John. Skiing, rafting and driving are not good analogies.