Cavern and cave

[MikeFerrara]

The rule that most people forget and that is often bent/violated is the line of sight to the SURFACE. If you can't see the surface ripples, you are technically in violation of cavern diving limits. You don't have to see the surface where you will exit, but you have to be able to see the open surface somewhere, even if it's the far end of the opening 500' away.

I WAS a cavern instructor and I never heard of that one.

 

[H2Andy]

the definition of a cavern dive were just changed by the
NSS-CDS as follows:


a. daylight and emergency ascent zone of the cavern within sight of the surface entrance

b. 200 feet linear from the surface

c. 100 feet maximum depth

d. 40 minimum starting visibility

e. no decompression diving

f . no restrictions (areas too small for two divers to pass together)

g . no original exploration

 

[loosebits]

the definition of a cavern dive were just changed by the
NSS-CDS as follows:


a. daylight and emergency ascent zone of the cavern within sight of the surface entrance

b. 200 feet linear from the surface

c. 100 feet maximum depth

d. 40 minimum starting visibility

e. no decompression diving

f . no restrictions (areas too small for two divers to pass together)

g . no original exploration

I was taught 70' max for cavern, 100' max for intro. They just added the 200' (was 130') distance from surface. This is probably to account for some of the gigantic 747-can-turn-around sized caverns in Mexico. Also, no goal/objective oriented diving (let's make it to the reaper sign). There are some other ones like the dive must be started against the flow, rule of thirds, etc.

 

[H2Andy]

NSS-CDS limit is 100 max depth for cavern:

http://www.nsscdstraining.com/

 

[adder70]

It was something I thought I remembered from cavern, and the pic on the training page shows shaded areas that seem to correspond to line of sight restrictions. I don't have my manual handy, so maybe someone with a larger version, say from the manual, could enlighten us as to the reason certain areas are shaded. (Specifically, the area above the diving zone, and the area below and to the FAR left, just the part with the non horizontal boundary.)

Hey, I could be wrong!

 

[roakey]

The two areas you mention put you out of sight of the opening. The opening must be visible at all times for a cavern dive.

Roak

 

[Kim]

Hi guys-

Could someone help me out here. As I said in an earlier post I'm certified IANTD Overhead Environment, I don't remember any instruction about distance limitations except for primary light source and the rule of thirds. I'm not sure that this certification exists anymore but would be interested to hear from you as to EXACTLY what it qualifies me to do!! Do these depth/distance rules apply to me or are they rules for a different certificate than IANTD? I was under the impression that I was certified for cavern/cave and wreck penetrations using a line - no deco - rule of thirds - sunlight visible!

 

[gehadoski]

Please help me out!!

please define IANTD and Rule of thirds. Sorry cause I am asking many questions may be some of these questions seems silly but I like to learn and gain more information. Actually I am on this board for that. I gained alot of information from this board. I thank you alot for your help

 

[Snowbear]

Do these depth/distance rules apply to me or are they rules for a different certificate than IANTD? I was under the impression that I was certified for cavern/cave and wreck penetrations using a line - no deco - rule of thirds - sunlight visible!

IANTD's website, from which you can download the complete standards:

Cavern and Wreck

The Cavern and Wreck training programs develop wreck diving skills and cavern diving skills within limits of light penetration. These programs are designed to ensure divers are aware of self-responsibility and capable of risk management in overhead environments. The programs may be taught using either air or Nitrox.

 

[SDAnderson]

please define IANTD and Rule of thirds.

International Association of Nitrox and Technical Divers. One of several agencies with advanced training programs. Others popular ones in the States (all are international in scope) include Technical Diving International and Global Underwater Explorers.

IANTD TDI GUE​

The rule of thirds is a gas management safety plan. Basically, it says you should turn your dive (start back) when you have used 1/3 of your gas. This leaves you 1/3 of your gas to get back with and 1/3 of your gas for a reserve in case something goes wrong. This last third is sometimes called your buddy's gas, since it's what he'll use if he has a catastrophic failure and you have to share gas on the way back. It's a good rule but sometimes too conservative and sometimes not conservative enough.

There's no such thing as a stupid question, just stupid people. The stupidest are the ones that don't ask questions.