Inadvertent gas switch on Shearwater?

[beester]

now, though slightly different, one thing i remind my students is to only turn "on" gases they will actually dive on the shearwaters. Otherwise the calculations will be off as they take into account ALL active gases. There is a recent article on the shearwater website on that topic.

True. Active gasses will affect the calculation of your deco time or time to surface (TTS), at least as long as you are before a switch. After of course

 

[WarrenZ]

@lynnpartridge Has anyone contaced Shearwater for their input on why this is happening?

 

[kelemvor]

I've never had it happen on petrel 1, but then I have always disabled extra gasses unless I need them.

 

[tursiops]

There was a NOAA diver who died a few years ago on the Aquarius habitat due to random -- but just the right sequence -- button pushes on his Inspiration CCR handset. The pulses came from nearby underwater air-driven jackhammer. It is the "million monkeys on a million typewriters for a million years accidentally writing Shakespeare" issue.

I suppose the SW problem could be mitigated by requiring one of the buttons (left?) to be held in while the other (right?) button is changing the gas.

 

[stuartv]

Stuart: Before you decide on an iX3M or OSTC4, just be aware that they're both at least as big as the Perdix. Though I don't have an issue with the form factor, I remember you disliking the size. The Ratio and OSTC4 aren't small computers by any stretch of the imagination.

My issue is thickness. The Perdix is still 39mm at its thickest dimension. The OSTC is way thinner and I think the iX3M is also thinner.

The OSTC being Open Source is really appealing to me....

 

[victorzamora]

The Perdix is 39mm at its thickest, yeah. Once on your arm, the Ratio and the OSTC4 should be about the same profile...I know the iX3M is and the OSTC4 looks at least as big. The Perdix at least wraps around your arm, so it's not sticking 39mm up from the "top" of your arm (if that makes sense).

 

[CuzzA]

When PDC shopping one thing I didn't like about the Petrel after playing with it was the buttons on either side. It seemed awkward contorting my wrist to make changes when it was mounted on my arm. Seeing this thread makes total sense you could inadvertently make unintended changes to the computer during a dive. Aside from screwing up a current dive it could really screw up a repetitive day of diving.

My current PDC has four buttons which are on the side parallel to my arm. Four may seem like a lot but it's actually quite convenient. For example, during a dive one button is dedicated to pulling up my compass. There's no wrist contorting and I've never inadvertently hit a button.

In the future Shearwater should take another look at their button configuration.

 

[AJ]

When PDC shopping one thing I didn't like about the Petrel after playing with it was the buttons on either side.

That's personal, I don't mind the positioning. Had more trouble operating my Suunto D4i because of the tiny knobs.

Seeing this thread makes total sense you could inadvertently make unintended changes to the computer during a dive.

Has not happened to me in over 100 dives, but it could be happening in some circumstances. Don't know.

Aside from screwing up a current dive it could really screw up a repetitive day of diving.

Not really, SW computers don't lock you out. You can always fall back on tables or phone app's to do the math. You can reset the computer as far as tissue loading goes by pulling the battery if you want to.

 

[Doby45]

In almost a 100 dives I have never had my Petrel 2 change anything on its own. Especially during a dive. Actually while in dive mode if you want the "short cut" gas change you have to hold both the left and right button at the same time. Then switch to the gas and confirm it. I discovered this while I was trying to turn on my compass (which only requires a right button press while in dive mode).

EDIT : This is also while in rec mode.

 

[stuartv]

When PDC shopping one thing I didn't like about the Petrel after playing with it was the buttons on either side. It seemed awkward contorting my wrist to make changes when it was mounted on my arm..

That is one of the several reasons I sold my Petrel 2. Reaching the button on the "far" side (e.g. left button with right hand), especially if you are trying to hold the computer straight out in front of you, is very awkward (for me, anyway).

I also couldn't feel the buttons very well - especially with gloves on - to operate them without having to actually look at my finger placement.

This new (to me) issue of accidental button presses is just one more reason why I don't miss my Petrel.

You may not have ever had an accidental button press on a SW, but it seems like it would be pretty hard to argue against it being a lot more likely to happen with buttons squarely on the side than buttons on the front or top.