GUE Cave 2 and Tech 1

[hweijie]

Hi,

I'm wondering as a cave 2 divers, your limits is 30m (100ft) deep caves. If you separately being taught tech 1 (not in overhead environment), does it allows you to have the skill set to dive caves that are deeper than 30m?

Thanks

 

[PfcAJ]

In my opinion I believe it does give you the needed skills. The ideas behind where to drop a deco bottle are the same as what you learn in C2, and gas management is discussed in T1 in regards to maintaining enough gas volume to get back to your deco bottle in event of a failure (or two) are the same.

As with anything, start slow, add complexity gradually.

Fwiw, I took all my tech classes in OW and apply the same stuff to deep cave dives all the time.

 

[hweijie]

I see. Thanks.. I should start slow and add complexity gradually..

 

[ScubaInChicago]

T1 limits you to a single deco gas, 30min of unadjusted deco and no stages whereas C2 allows stages and a deco gas. Without knowing the intended dive profile, it's hard to say weather it's a good idea. I would lean toward the conservatism of T1 standards but you're faced with the dilemma of gas logistics. 150'>20' is not ideal and the 70' bottle as an alternative might be difficult depending on the profile of the cave. I would make sure you've sharpened your pencil and know what your min gas, usable gas, and reserves are and then add for conservatism.

 

[ucfdiver]

T1 limits you to a single deco gas, 30min of unadjusted deco and no stages whereas C2 allows stages and a deco gas. Without knowing the intended dive profile, it's hard to say weather it's a good idea. I would lean toward the conservatism of T1 standards but you're faced with the dilemma of gas logistics. 150'>20' is not ideal and the 70' bottle as an alternative might be difficult depending on the profile of the cave. I would make sure you've sharpened your pencil and know what your min gas, usable gas, and reserves are and then add for conservatism.

Couldn't you show your T1 card which was taught using 50% at the 70ft stop and then show your Cave 2 card at the 20ft stop which covered 100% o2? This is, or course the scuba police are present In all seriousness this seems like NBD. If you know how to calculate minimum deco gas from both T1 and C2, I would assume you could calculate everything you need to safely execute the dive being described here.

 

[PfcAJ]

70 bottle is really what you want for a 150' cave dive. You don't HAVE to switch to it at 70ft if there's not a good spot at 70.

Both 50% and oxygen is ideal.

 

[ScubaInChicago]

70 bottle is really what you want for a 150' cave dive. You don't HAVE to switch to it at 70ft if there's not a good spot at 70.

Both 50% and oxygen is ideal.

It's where I was going with it. You end up needing another complimentary gas (bottom stage, second deco gas) really quick in order to do the dive safely. You also have the nagging issue of deco. I personally see it laying the roadwork to exceeding ones training limits very quickly. The other big issue we haven't covered is who are you doing this dive with?

 

[PfcAJ]

I was in a similar conundrum once. I had c2 and t1 for quite some time.

At some point you've gotta be a grownup diver. There isn't a "class" for every single eventuality. Use what you've learned and apply it.

Short BTs in the 20-30min range at and around 150ft is a reasonable thing to do with a single deco gas. Bring reserves and enjoy the new stuff you get to see.

folks have ZERO problem with doing the same deco time at 20ft on oxygen following dives in the 80-100ft range. I don't see a huge difference in a slightly deeper avg depth and taking a 50% bottle vs 100%. Youve got less time at depth to handle stuff that goes sideways, but you've also got less distance to worry about covering since you're practically limited to 10-15mins of penetration time. These are the same issues one faces when transitioning from super shallow caves (40-60ft) to stuff that's 80-100.

 

[CptTightPants21]

Keep waiting for TSandM to respond to a GUE question. Just goes to show you how much of an effect she had on this board.


Gone, but not forgotten.

 

[ScubaInChicago]

At some point you've gotta be a grownup diver. There isn't a "class" for every single eventuality. Use what you've learned and apply it.

Agreed, you should have the tools to do a strict T1/C2 dive properly which will yield short penetration times. The moment you bring a stage to help with logistics/safety, you've crossed into T1+/T2 territory which is a whole other bag of worms. I don't believe we discussed gas breaks in our C2 class but these dives teeter on those boundaries that also deserve consideration. My overall point is that the dives can be done, but need to be planned AND executed with those limitations in mind. An overhead environment is not the most forgiving place to experiment within.