Another computer quandary.

[KenGordon]

What do they tell you to do?

They go red indicating you are above the stop. I'm guessing that eventually they will give you the next shallower stop as offgassing continues. They can do this as they run a very simple disolved gas model. Once you are above the stop you are still offgassing, a bit faster than at the stop, and eventually will be 'allowed' past the stop in any case.

The various computers which lock out might have two sorts of reasons to do so:

The maths may actually be broken, the model assumptions (e.g. ascent rate) violated or the profile might be outside the bounds of testing.

To actively discourage users from the behaviour, or to make them actually notice they did something 'wrong'.

Computers like the shearwaters were originally built to match paper plans from desktop software. Their purpose is to keep the diver on something resembling that plan. That is not the same purpose as the 'keep jumping in and swimming about repeatedly each day' use that computers which will lock you out were built for.

 

[rongoodman]

The Shearwater will display a message regarding missed deco, which you must acknowledge in order to clear. The Liquivision displays alarms and messages after surfacing for a period of time.

 

[BRT]

They go red indicating you are above the stop. I'm guessing that eventually they will give you the next shallower stop as offgassing continues. They can do this as they run a very simple disolved gas model. Once you are above the stop you are still offgassing, a bit faster than at the stop, and eventually will be 'allowed' past the stop in any case.

The various computers which lock out might have two sorts of reasons to do so:

The maths may actually be broken, the model assumptions (e.g. ascent rate) violated or the profile might be outside the bounds of testing.

To actively discourage users from the behaviour, or to make them actually notice they did something 'wrong'.

Computers like the shearwaters were originally built to match paper plans from desktop software. Their purpose is to keep the diver on something resembling that plan. That is not the same purpose as the 'keep jumping in and swimming about repeatedly each day' use that computers which will lock you out were built for.

Thanks

 

[dmaziuk]

The Shearwater will display a message regarding missed deco, which you must acknowledge in order to clear. The Liquivision displays alarms and messages after surfacing for a period of time.

I wonder if anyone knows how much you can "bend" them before the maths breaks. You have to remember that digital computers operate on finite quantities that will at some point overflow, so it will break if you push it far enough.

 

[scubadada]

I wonder if anyone knows how much you can "bend" them before the maths breaks. You have to remember that digital computers operate on finite quantities that will at some point overflow, so it will break if you push it far enough.

This thread has gone off in the wrong direction. You shouldn't violate your computer's deco recommendations due to increased risk of DCS. Whether your computer puts you into VGM for 24 hours or not is not that important, the fact that you got there is the important point.