Question Do you cave dive exactly the way you teach people to cave dive? Do you cave dive the way you were taught?

[steinbil]

things i dont do - a knotted secondary tie off (just a wrap or hitch)

I'm confused. What is a "knotted" tie off? I was taught a double wrap and lock, which seems very secure yet can be removed without too much effort coming out.

 

[lermontov]

I'm confused. What is a "knotted" tie off? I was taught a double wrap and lock, which seems very secure yet can be removed without too much effort coming out.

some teach a knotted tie off that cant come undone in either direction without physically untying as opposed to a wrap and lock

 

[SpaceX Aquanaut]

I dont follow -if you started with 200 and you turn at 130 youve used 70 Bar to get where you are which means you need 140 to get you and your buddy back to surface? and thats bare minimum and with empty tanks

Read again Lermie (I think you missed a paragraph):

Suppose you originally planned a wreck penetration starting with 200 bar at the entrance, with an openwater Rock Bottom minimum gas reserve of 50 bar. So 200 minus 50 bar equals 150 bar usable for the penetration --Modified Thirds of this value is 50 bar (one-third of 150 equals 50), so you would turn-around for egress when you consume 50 bar of gas with an actual SPG reading of 150 bar. If you needed to do a gas-sharing emergency egress with your buddy at this point, you would together need 100 bar to get out of the wreck, with 50 bar Rock Bottom remaining to get both of you to the surface (or your Oxygen deco bottle stop of 6m).

Lets say you used up 30 bar already getting to the entrance of the wreck for a total of 170 bar pressure available --can you quickly recalculate Modified-Thirds?

No problem with bar pressure metrics: 170 bar minus 50 bar Rock Bottom yields 120 bar usable for the penentration; One-Third of 120 bar is 40 bar which is your new Modified Thirds turn pressure value. Therefore you would turn the dive when you consume 40 bar for an actual turn pressure SPG reading of 130 bar (170 bar minus 40 bar equals the actual turn pressure SPG reading of 130 bar).

 

[inquis]

I dont follow -if you started with 200 and you turn at 130 youve used 70 Bar to get where you are which means you need 140 to get you and your buddy back to surface?

The ascent portion of his wreck example is taken off the top, making it "modified thirds". You just need to get back to that spot on the bottom with the ascent gas remaining. This effectively ignores the gas used on "stuff" during the original descent that you won't do in an emergency ascent (e.g., bubble checks, hooking up someone's inflator that came loose, checking/securing the anchor [wreck], searching for the mainline [cave], differing descent/ascent rates, etc.).

 

[rjack321]

Just finished C1 at the start of this month. It is part of the lost buddy protocol. We were expected to know (and remember - not write down anywhere) the gas pressure at various points during the dive, and to calculate needed gas to exit to determine how much gas you can use for searching for the buddy. So the awareness and ability to recalculate is trained.

However, we did not during the course recalculate gas during a dive to extend it by branching out, not sure if that is something still being taught. Our dives crossing a T, we did one complete dive on either side, recalculating at the surface.

Yes in addition to lost buddy I recall being expected to recalculate at a T while underwater

 

[DiveLikeAMuppet]

I was never taught such a thing and I am curious who is actually teaching the group huddle & point method described here. Sounds like something students would do if the instructor failed to teach them a better way.

Multiple instructors from a pretty famous shop - don't want to trigger a politics discussion.

I will add few from my naughty list:

• Using clothing pegs if the line is too thick for cookies... it's also faster in thick drygloves!
• At intro to cave level, diving fourths instead of sixths (1/3 of 2/3) on repeated dives in certain caves and diving tighter caves
• At intro to cave level, limited navigation (think a naughty T or a jump in simple places)
• In wrecks, not running a line - it usually goes as "just a looksie, it will take too much time to run the line" -> "hmmm that's a bigger space than I expected, I wonder what's round the corner" -> "cr*p I should've been running a line" ... but I'm actively getting better at this

 

[Mobulai]

inside me are 2 dogs:
one wants to ask for clarification about all them naughty things, and the other thinks it’s probably best I unwatch/stop following this thread till I actually start/finish (at least) an intro to cave class (min ETA a year from now)

 

[SpaceX Aquanaut]

Multiple instructors from a pretty famous shop - don't want to trigger a politics discussion.

I will add few from my naughty list:
<snip>

• In wrecks, not running a line - it usually goes as "just a looksie, it will take too much time to run the line" -> "hmmm that's a bigger space than I expected, I wonder what's round the corner" -> "cr*p I should've been running a line" ... but I'm actively getting better at this

HIMJS Fumizuki Destroyer Engine Room with Sidemount: I’ll just tie-off my main reel, and do a “visual jump” to go look at some dials & levers -it’s only less than 3meters away from the corridor. . . (didn’t realize the different perspective returning back, looking past the Boilers & piping which I didn’t reference coming in, now going back to the corridor -no silt-out- just disorientation with momentary confusion being lost -in only a 3m visual jump.

 

[jadairiii]

Lost Line Drill.
I hate that drill. It takes up way too much time for something that, in reality, the lesson is, "DON'T LOSE THE LINE!!!!!!!!"

I cant say this is true, but I wonder how many C1 divers wash out on a proper lost line drill due to panic/claustrophobia being blacked out and having to function? I watched a guy do it in my C1 class, that was a full cave diver and cavern instructor from another agency. That guy hated it when we went "black out/lights out" and on that drill he lost his sh*t, and it was in an easy cave to do the drill in.

Sometimes the drill isn't the real lesson.

 

[rjack321]

Multiple instructors from a pretty famous shop - don't want to trigger a politics discussion.

It's not politics its poor teaching and poor role modelling.

• At intro to cave level, diving fourths instead of sixths (1/3 of 2/3) on repeated dives in certain caves and diving tighter caves
• At intro to cave level, limited navigation (think a naughty T or a jump in simple places)

Both of these are part of the standards in GUE C1. So are they taught this way from the get go and not some kind of after the fact standards deviation for those folks.