I'd like to see the varied definitions differentiating cavern from cave diving. I completed Intro to Cave in Spring of '00, and as I understand it, NSS-CDS has changed their definition since I was trained. At that time, NSS-CDS and IANTD were similar enough that I was offered cards from both agencies.
From my NSS-CDS Cavern Diving Manual, cavern diving in standard recreational scuba gear follows these limits;
Direct Sunlight Zone - diver can see the opening (entrance/exit). If you can not see the opening but it is not pitch black, you are in the ambient-light zone. When it is pitch black and you can see nothing without lights you are in the zone of total darkness. Cavern diving is only in the direct-sunlight zone.
130' Maximum Linear Distance from the Surface - Cavern divers must stay within a linear distance of 130' to the surface. Linear distance includes the depth of the entrance plus the distance of penetration. Examples; 30' deep entrance plus 100' penetration, 50' deep entrance plus 80' penetration, 70' deep entrance plus 60' penetration.
70' Max Depth - Below 70' air reserves for dealing with emergencies are too limited and the margin for error becomes too critical.
No Restriction - Buddy teams should be able to comfortably swim side by side. If divers have to swim single file due to localized narrowing that is considered a restriction. Cavern divers are not permitted to pass through restrictions in part because sharing air with standard scuba through a restriction is nearly impossible.
40' Minimum Visibility - The minimum visibility acceptable for cavern diving is 40'.
No Decompression Limits - Cavern divers should stay well within the no-deco limits. When cavern diving, bottom time is the time from leaving the surface until returning from the cavern to a depth of 10' in open water(not ending at start of ascent). Most experienced cavern divers stay within 80% of NDL limits, to allow for any unexpected delays during exit.
Air Supply Limitations - One of the three leading causes of death in underwater caves is failure to reserve adequate air for exiting. This requires at least as much air in each cylinder as both divers (buddy team) used coming in on the two seperate cylinders (basic rule of thirds).
If you are in any of these following situations, you are technically in cave diving territory; ambient-light zone or zone of total darkness, more than 130' linear from surface, deeper than 70', past a restriction less than 2 divers wide, less than 40' visibility, more than 3 minite required saftey stop. Violating the rule of thirds does not put you in cave diving territory, you are just very foolish.
I'd like to hear from more than just North America; CDAA (Australia), CDG (Great Briton), IANTD, TDI, GUE, NACD and any I've missed. Not really interested in what PADI, NAUI and similar mainstream agencies have to say.
From my NSS-CDS Cavern Diving Manual, cavern diving in standard recreational scuba gear follows these limits;
Direct Sunlight Zone - diver can see the opening (entrance/exit). If you can not see the opening but it is not pitch black, you are in the ambient-light zone. When it is pitch black and you can see nothing without lights you are in the zone of total darkness. Cavern diving is only in the direct-sunlight zone.
130' Maximum Linear Distance from the Surface - Cavern divers must stay within a linear distance of 130' to the surface. Linear distance includes the depth of the entrance plus the distance of penetration. Examples; 30' deep entrance plus 100' penetration, 50' deep entrance plus 80' penetration, 70' deep entrance plus 60' penetration.
70' Max Depth - Below 70' air reserves for dealing with emergencies are too limited and the margin for error becomes too critical.
No Restriction - Buddy teams should be able to comfortably swim side by side. If divers have to swim single file due to localized narrowing that is considered a restriction. Cavern divers are not permitted to pass through restrictions in part because sharing air with standard scuba through a restriction is nearly impossible.
40' Minimum Visibility - The minimum visibility acceptable for cavern diving is 40'.
No Decompression Limits - Cavern divers should stay well within the no-deco limits. When cavern diving, bottom time is the time from leaving the surface until returning from the cavern to a depth of 10' in open water(not ending at start of ascent). Most experienced cavern divers stay within 80% of NDL limits, to allow for any unexpected delays during exit.
Air Supply Limitations - One of the three leading causes of death in underwater caves is failure to reserve adequate air for exiting. This requires at least as much air in each cylinder as both divers (buddy team) used coming in on the two seperate cylinders (basic rule of thirds).
If you are in any of these following situations, you are technically in cave diving territory; ambient-light zone or zone of total darkness, more than 130' linear from surface, deeper than 70', past a restriction less than 2 divers wide, less than 40' visibility, more than 3 minite required saftey stop. Violating the rule of thirds does not put you in cave diving territory, you are just very foolish.
I'd like to hear from more than just North America; CDAA (Australia), CDG (Great Briton), IANTD, TDI, GUE, NACD and any I've missed. Not really interested in what PADI, NAUI and similar mainstream agencies have to say.
