Tech Diving and Air Integration

[DevonDiver]

When I started diving I was alway taught to show the SPG to my buddy and they would reciprocate, I frequently use signals too, however as I usually have a camera in one hand it is difficult to make a T sign for 100

A reminder that this thread is in the tech diving forum. There's probably an assumption that those contributing would have received training beyond entry-level - which would include more precise communication skills once technical level training has commenced.

Are you suggesting that there are technical diving instructors out there who don't teach comprehensive hand signalling... and still use open-water level (T=1/2 tank) signals?!?

 

[beaverdivers]

I was really just curious whether there was any added benefit to a computer and a bunch of transmitters, which is what a couple of people were saying was possible...., but I don't see that the extra expense is worth it for the marginal convenience of looking at my wrist rather than an SPG.

The benefit is the extra transmitters are not only tracking the amount of gas, but putting those mixes into the algorithm and tracking both nitrogen and O2.

 

[James R]

The benefit is the extra transmitters are not only tracking the amount of gas, but putting those mixes into the algorithm and tracking both nitrogen and O2.

Oh come on now, you should know better than this.

Different gas mixes change your dive and deco requirements and would not be tracked because of the transmitters! You still do the gas switch on your computer to the programmed mix for the deco cylinder you switch to. A transmitter doesn't make your computer do anything extra aside from tracking tank pressure and pressure-related data, and again, has no impact on the algorithm being used or your nitrogen/02 exposure etc.

 

[beaverdivers]

A transmitter doesn't make your computer do anything extra aside from tracking tank pressure and pressure-related data, and again, has no impact on the algorithm being used or your nitrogen/02 exposure etc.

When you switch to a different tank ( transmitter ), you are in fact switching all the info; the mix of the gas in the tank and the amount of gas.

Are you saying, changing to a different mix has no impact on the algorithm?

Moreover, the air integrated computer takes into account workload.

 

[mathauck0814]

When you switch to a different tank ( transmitter ), you are in fact switching all the info; the mix of the gas in the tank and the amount of gas.

Are you saying, changing to a different mix has no impact on the algorithm?

Moreover, the air integrated computer takes into account workload.

I believe he's saying that the transmitter has no baring on the algorithm and that switching gasses on a non AI computer accomplishes exactly the same thing.

 

[James R]

I believe he's saying that the transmitter has no baring on the algorithm and that switching gasses on a non AI computer accomplishes exactly the same thing.

Reading comprehension is a beautiful thing. Thanks. This is exactly what I meant.

 

[randy88k5]

This is to answer John's questions asked earlier in the thread. I just got back to reading this thread today.

My main computer is a Liquivision X1 (thanks Jax), and my backup is a Galileo Luna with the PMG upgrade (have not got the trimix upgrade for it yet). Both computers are set for the gasses before the dive. I wear a slate and the X1 on my left wrist and the Luna on the right. I use V-Planner and write the desired profile on the slate. I use the Luna for depth, pressure, temperature, and remaining bottom time (unless really low vis, then use X1 for depth and time). With the bottom and deco mixes entered in the Luna, it displays the remaining bottom time you can have, and still have a safe ascent with the deco gasses, since it tracks instantaneous SAC/RMV. When ascending, I mainly follow my slate and X1, since deeper stops are required with these. I change gasses on the X1 before the Luna, since I am following that schedule more closely. By the time I am at the last stop, the computers are within a few minutes of each other. I will clear them both before surfacing.

So I have a couple of questions for those who use AI in their tech diving:

1. If you are using a computer originally purchased for recreational diving and are using it for tech diving in gauge mode, would you have bought the computer new for that purpose (which is understandable), or would you have instead gone with a bottom timer and spg?

Sort of. For years, I was using an Aladdin Pro. After a long dive vacation and a misreading of the owner's manual, I didn't back the computer up enough, and ended up losing over half of the dive data. That pissed me off, and being air only, I wanted to find something newer and with more options and better memory. I was talked into buying a Galileo Luna. The person told me it would do everything I needed and I would never outgrow it. I had it for less a few months before I learned that multi-gas was an add-on. I posted a thread a while back about selling it for a better tech computer, or just keep using it as a bottom timer as needed. I decided to keep it. Even though I do like it, I doubt I would buy it again.

2. If you are using an AI computer with all functions operating for deep or prolonged air/nitrox diving with decompression on different gases, did you purchase the computer for that purpose, or was it one you already had been using for recreational purposes?

I wanted a computer that had these features for both rec and tech, so I bought the Luna. I later learned it was not the best computer for tech diving. I kept it anyway. The AI came with it, so I used it. I did not buy it specifically for the AI feature.

3. If you are using an AI computer with all functions operating for deep or prolonged air/nitrox diving with decompression on different gases, do you plan to get trimix training in the future, and, if so, will you be getting a new computer when you do?

I have trimix training, and I used my current setup in the class. It worked fine. FWIW, I have run the Luna in multi-gas mode set to the correct O2 percentages when diving trimix. I followed my X1 and tables for the proper ascent schedule. The Luna was clear by the time I surfaced. YMMV.

4. If you feel AI is valuable for one gas, why is it not valuable for the other gases? If it is not valuable for the other gases, why is it valuable for the first one?

I really only 'need' the SAC/RMV calculations and RBT when on the bottom. I don't really feel the consumption rates and times displayed on the Luna during deco are necessary. However, if someone wishes to, they can buy more transmitters and put them on all of their cylinders. I don't necessarily view the SAC/RMV and RBT calculated when using AI as valuable in the necessary sort of way, but more valuable in the convenient sort of way.

 

[Paulmal]

I currently own a DG03 but did not get AI, have considered it for rec dives. I do not feel it is all that useful so I have yet to buy a transmitter, better uses for the money like reels, tanks, regs, but I'd anyone wants to sell me one for $50 I would consider it. I am looking at buying a shearwater because they make top of the line computers and lack of AI is fine with me. I feel AI on a tec dive is ok if you want it and are ready to take the extra risk, but for me I would rather spend money elsewhere and not have the extra failure points, how ever minimal or major you feel they may be. It all comes down to risk tolerance, some have more than others. Do whatever floats your boat.

 

[HowardE]

I have trimix training, and I used my current setup in the class. It worked fine. FWIW, I have run the Luna in multi-gas mode set to the correct O2 percentages when diving trimix. I followed my X1 and tables for the proper ascent schedule. The Luna was clear by the time I surfaced. YMMV.

Why do you think that is then? Probably because you can't tell the Luna you are diving helium...

If you are trimix certified, you can get the software update from SCUBAPRO... you just have to ask them and prove you're certified.

 

[Thalassamania]

BD: are you saying the the AI computers will automatically recognize when you change gases? That would be neat. Also, the workload adjustment is, I believe, totally useless. Not a bad concept but rather a poorly executed one.

That said, I use an AI computer. I like having all my information on my wrist and have not had any problems with lost signals. I especially like being able to monitor my buddy's gas. This made me feel much more secure when my son started diving with me at a young age.