Tank configuration

[Dogbowl]

Thank you for the long reply.

1) Sounds like the next time I am down in the Toronto area, I will go see them. And it is a 4 hour drive. 5 hours only in bad weather.

Just FYI, Dan’s Dive Shop is not in Toronto. They are in St. Catharines, about 1.25hrs drive from Toronto proper.

 

[kensuf]

Really? Do tell...

Orange Grove, September 2016 for starters.

 

[swimmer_spe]

Start here
William Hogarth Main - Wikipedia

I think you have been given some pretty sound advice here re progressing into overhead diving considering your current comfort level with basic skills. ..so I will not repeat those warnings.

I will say that some people pursue advanced diving more for the challenge or just some need to "level up".

I appreciate your transparency and think you could benifit from thinking through a few things.

It's kind of hard for me to imagine being cavern certified withought exposure to some of the most basic concepts. Read up on the Hogartian principles for gear rigging. Get yourself used to the idea of "primary donate". This is consistent with all cavern/cave/tech training that I have seen. So if you want to play in this sandbox, you should gain comfort with it.

If you run into an OOA diver in a cavern, you should expect them to go for the reg in your mouth and be prepared to quickly offer this reg and THEN switch to your backup. This is a fundamental skill. If you are incapable of getting comfortable with this, ....please stay out of caverns and caves.

I am not doing it to "Level up", or just chase cards. I have certain things I would like to do when it comes to diving. Diving a cenote is one of them. Since I enjoyed it, I will be doing more of it. I will only dive to the training I have received.

The OOA. I will be honest. I never remember which to give, so if someone goes for my primary, I would simply take the secondary. However, I was taught that you open your arms and then let them take the secondary, which on my setup is yellow. I would not panic if you went for the one in my mouth though.

 

[swimmer_spe]

Just FYI, Dan’s Dive Shop is not in Toronto. They are in St. Catharines, about 1.25hrs drive from Toronto proper.

Ok, then, ya, about 5 hours.

 

[tbone1004]

I am not doing it to "Level up", or just chase cards. I have certain things I would like to do when it comes to diving. Diving a cenote is one of them. Since I enjoyed it, I will be doing more of it. I will only dive to the training I have received.

The OOA. I will be honest. I never remember which to give, so if someone goes for my primary, I would simply take the secondary. However, I was taught that you open your arms and then let them take the secondary, which on my setup is yellow. I would not panic if you went for the one in my mouth though.

so if you are only diving to the training that you have received, why are you interested in doubles or sidemount which are not going to benefit you at the cavern level?
In true overhead training, you are trained to donate primary. You do not open up arms and let them grab stuff, you are an active participant in the OOA scenario by donating the regulator. This is not optional in any form of sidemount or doubles configuration outside of BSAC which is in the UK only

 

[swimmer_spe]

Can you explain what you were taught about gas management? I'm confused about your mention if coming up with "half the gas I went down with"

Your cavern cert, and best practice, limit you to using 1/3 of a single tank volume for penetration, and 1/3 for exit, meaning you should surface with at least 1/3 remaining. With doubles, it is 1/6 in, 1/6 out, leaving 2/3 remaining. It makes no difference whether it is the first or second dive.

So, right now I only know singles. I dive with 1/3 going, 1/3 coming, and 1/3 for emergency. I have always dove that way, even prior to cavern course.

As I understood it, diving SM, 1/6 in, 1/6 out, 1/6 for emergency. That mean you come out with roughly 1/2 of your gas you started with, if both tanks are full.

Now, here is where I get confused: On your second dive with those tanks, is it still 1/6, or is it 1/3?

 

[swimmer_spe]

so if you are only diving to the training that you have received, why are you interested in doubles or sidemount which are not going to benefit you at the cavern level?
In true overhead training, you are trained to donate primary. You do not open up arms and let them grab stuff, you are an active participant in the OOA scenario by donating the regulator. This is not optional in any form of sidemount or doubles configuration outside of BSAC which is in the UK only

The interest in SM or doubles was purely because it was made out that everyone who dives in an overhead environment, which even cavern diving is, should have redundancies.

As far as who gets what, when we go through the pre dive checks, if someone of a higher certification tells me that they do it one way or another, I follow that. I know for SM, you give them your long hose, and you take your short hose.

 

[Dogbowl]

I am not doing it to "Level up", or just chase cards. I have certain things I would like to do when it comes to diving. Diving a cenote is one of them. Since I enjoyed it, I will be doing more of it. I will only dive to the training I have received.

The OOA. I will be honest. I never remember which to give, so if someone goes for my primary, I would simply take the secondary. However, I was taught that you open your arms and then let them take the secondary, which on my setup is yellow. I would not panic if you went for the one in my mouth though.

I am still unable to follow the logic of why you think you need to go SM or BM. All this talk and at the end of the day, you just want to dive cenotes with a guide?

You mentioned that when it comes to diving, diving a cenote with a guide is one of the things you’d like to do. Care to share what else you want to do that maybe is contributing to your want to go SM or BM?

I cannot see the link between “I wanna dive cenotes with a guide” and “I want/need to go SM or BM”.

Again if air is your issue, there are other better ways to help that. Perhaps a larger steel tank?

 

[JohnnyC]

So, right now I only know singles. I dive with 1/3 going, 1/3 coming, and 1/3 for emergency. I have always dove that way, even prior to cavern course.

As I understood it, diving SM, 1/6 in, 1/6 out, 1/6 for emergency. That mean you come out with roughly 1/2 of your gas you started with, if both tanks are full.

Now, here is where I get confused: On your second dive with those tanks, is it still 1/6, or is it 1/3?

1/6th in, 1/6th out, is 2/6ths of your gas for the dive. You have 4/6ths as reserve.

The limits of your certification state 1/6th of your starting pressure. That is irrespective of whether or not you do one dive or seven dives on your tank(s). Example, let's say you have a set of twins at 3000 psi. 1/6 is 500 psi. So 500 in, 500 out. You should have 2000 psi left when you surface. Your next dive, you're limited to 333 in, 333 out. You should surface with 1334 psi.

I'm seriously concerned that this was not covered in your cavern class. Everything mentioned in this thread is the most basic set of rules for overhead diving.

As for the guided Mexican cavern dives, they're all designed so that tourist divers can dive the cavern line at 1/3rds. Have you been in the situation where you have cut the groups dive short because of your rapid air consumption? If the answer is no, there's no point to doing anything else.

 

[swimmer_spe]

I am still unable to follow the logic of why you think you need to go SM or BM. All this talk and at the end of the day, you just want to dive cenotes with a guide?

You mentioned that when it comes to diving, diving a cenote with a guide is one of the things you’d like to do. Care to share what else you want to do that maybe is contributing to your want to go SM or BM?

I cannot see the link between “I wanna dive cenotes with a guide” and “I want/need to go SM or BM”.

Again if air is your issue, there are other better ways to help that. Perhaps a larger steel tank?

I am of the attitude that I should be diving similar equipment as those I am diving with. For instance, we all are diving dry, or we all have the same tank configuration. While there, I noticed others diving with SM. So, my logic tells me that maybe I should dive SM too.

There is a dive that is near Kingston/Cornwall ON which I have been suggested to dive doubles. So, I am considering doubles.

Air consumption is not the issue. I could be on a rebreather and still suck it back faster than many. That will get better the more I dive.

I want to dive with a guide as I do not know the cave systems. If a friend of mine knew them and invited me to dive with them, then I like would, but they are still a guide.

Other dives likely do not need doubles/SM.