Question re changing O2 settings in Galileo in mid dive

[Hatul]

I'm a single tank diver. A couple of times I forgot to set my Galileo Sol O2 setting for the Nitrox gas I was using and there was no way to change the O2 setting once I was in the water.

If I install the PMG firmware upgrade will I be able to change the O2 settings on my one tank of gas in the water?

 

[ontdiver]

I don't believe so. The same thing happened to me a few years ago when I had a Wisdom II, which would default back to 50% (?) after every dive. It was hard to ignore the numbers when this happened and this, among other things, was why I eventually bought a Luna.

 

[Hatul]

I don't believe so. The same thing happened to me a few years ago when I had a Wisdom II, which would default back to 50% (?) after every dive. It was hard to ignore the numbers when this happened and this, among other things, was why I eventually bought a Luna.

I was thinking I could tell the computer I have three tanks: air, EAN32, and EAN36 so I could swap from one to another underwater, but I'm not sure this would work as I've not used the PMG feature. Say I jump in the water with an Air tank but the computer was set to 36%, can I just switch the computer to the Air tank?

 

[flots am]

If I install the PMG firmware upgrade will I be able to change the O2 settings on my one tank of gas in the water?

AFAIK, once you're wet, the gas mix can't be changed.

 

[Dirty-Dog]

What you're looking for is a gas switching computer, which the Galileo is not.
The PMG upgrade allows you to program three different nitrox mixes, AND the depth at which you will switch gases. The screen shows your plan based on this pre-programmed data as well as an alternate plan that assumes you will do the entire dive on whatever the "default" gas is. There is no provision for changing mixes manually once you're in the water.
The functionality you're looking for is available in computers such as the Shearwater Petrel 2.

 

[kelemvor]

The PMG upgrade will allow you to switch gasses during the dive. The gasses must be defined before you submerge. So if you have 32 and 36 and 21 defined you could use it as a kludge. Assuming you aren't diving "best gas" mixes.

However, PMG is going to think you actually have a tank of each and recommend you switch to a better gas when appropriate. Which would probably be rather obnoxious if you don't actually have the other gasses available.

Here is the manual explaining exactly what the PMG upgrade does and now to use it. http://www.scubapro.com/media/176938/galileo_luna_pmg_multilanguage.pdf

FWIW, I've made that mistake before with a galileo.. it's a bummer. left it set for air when I was on nitrox. Fortunately this is easier to deal with than the inverse.

 

[Hatul]

Thanks for the replies. I made the mistake both ways, because typically I used air for my first dive (Cozumel) so I don't have to worry about exceeding the MOD on the deep dive, and EAN36 for the second shallow dive. Later I trained myself to set my Galileo to air at the end of each day of diving and to check the setting before each dive.

 

[JulesSCUBAPRO]

The gas settings cannot be changed underwater. The PMG is designed to be used with multiple tanks whose O2 % cascades up as you get closer to the surface. You would not be able to even program the lower gas percentage.

 

[vixtor]

On a Galileo with PMG you can definitely switch between gases underwater at any time, back and forth, as many times as you need (as long as the gases are predefined at surface, and enabled). The only "impact" will be that (a) the computer will ask you to switch to the optimal gas at the correct MOD, which you can ignore and it goes away, and (b) that at depth, the total ascent time will assume that you will use the optimal gases. While you ascend and ignore the switches, it will recalculate, but it will give you incorrect information about your total deco obligation during the dive.

The above issues are true for any other multi-gas computer.

What is worse than that is that if you use air and your computer thinks you have EAN32, then it will underestimate your nitrogen intake, and depending on how many minutes it takes you to correct the situation, your total real NDL will be shorter than estimated - so you should not stay in water until it goes to zero, and you cannot tell how sooner you should end your dive in reality - (or your deco will be longer than computed). The reverse (using EAN32 with an air configured computer) is not unsafe, it will just artificially shorten your NDL.