Perdix (Last deco STOP)

[guruboy]

In North America, REC does not include any mandatory deco.

Since you seem to have issues with the Perdix, why don't you sell it and get something that suits you better.

I have a nice ScubaPro G2 you might be interested in.

 

[tbone1004]

@npole
ok, here's the deal.
If you have a 6m last stop, then if you go above the 6m stop, the computer will start flashing warnings

If you have a 3m last stop, then you are free to go up to 3m on your final stop, but are not obligated to up to that depth. The downside to this is on long decompression dives when you are not using 100% O2 to decompress, your TTS will be off by a few minutes.

So why would you want to put 6m as your last deco stop?

 

[KenGordon]

The Perdix (AI) set in REC mode doesn't let you change the depth of the last deco stop, it's greyed and defaulted at 3 meters (10 feet), you cannot select 6m.
This is a limitation due to the fact that you cannot change the deco model and the default one requires a mandatory stop at 3m ... or for some other reason?
I feel odd to do a deco stop at 3 meters, and then a (optional) safety stop at 5m ... ?

My Petrel defaulted to last stop at 6. That lasted a whole dive.

I'd like to be able to have the TTS based on 6 but the ceiling go to 3

 

[scubadada]

Sorry to add a simple question, but, I could not find the answer in the Shearwater manual for the Perdix rec mode. Do I understand correctly that a Perdix, in rec mode, will give you a timed safety stop after fulfilling a deco obligation? Perhaps mistakenly, I have always thought a dive computer would give you a safety stop for a no-stop dive or deco stops if indicated.

I am only quite familiar with Oceanic computers. After fulfilling a deco obligation, no safety stop countdown is displayed, the computer reverts back to main screen. I spend extra time at my last stop/safety stop depth of 12-15 feet without a timer. My backup Nitek Q does not have a safety stop timer.

 

[lynnpartridge]

Sorry to add a simple question, but, I could not find the answer in the Shearwater manual for the Perdix rec mode. Do I understand correctly that a Perdix, in rec mode, will give you a timed safety stop after fulfilling a deco obligation? Perhaps mistakenly, I have always thought a dive computer would give you a safety stop for a no-stop dive or deco stops if indicated.

I am only quite familiar with Oceanic computers. After fulfilling a deco obligation, no safety stop countdown is displayed, the computer reverts back to main screen. I spend extra time at my last stop/safety stop depth of 12-15 feet without a timer. My backup Nitek Q does not have a safety stop timer.

In the OC Rec mode, there are a number of safety stop settings that can be chosen. You can keep them turned off and do your own safety stop as you see fit. You can choose 3, 4, or 5 minutes or you can choose adapt. If adapt is selected, then the computer will assign the best safety stop time based on your dive profile. If you have chosen a 5 minute safety stop, then do a decompression dive in this mode, it will impose a 5 minute safety stop in addition to your deco stops. If you are planning to do a decompression dive, you can turn off this recreational feature. Better yet, use the tech mode which gives divers a lot more control over their decompression diving.

 

[npole]

In North America, REC does not include any mandatory deco.

Since you seem to have issues with the Perdix, why don't you sell it and get something that suits you better.

I have a nice ScubaPro G2 you might be interested in.

I own a Cressi Giotto, a Cressi Newton, a Scubapro Mantis 2 and the Perdix AI. The Perdix is the best computer of the (above) lot for the recreational divings I do. But unfortunately it lacks of some basic things that could be easily fixed with a more "open" (configurable) GUI. A computer that suits me better would be a Perdix AI with a fully configurable interface.

 

[npole]

@npole
ok, here's the deal.
If you have a 6m last stop, then if you go above the 6m stop, the computer will start flashing warnings

If you have a 3m last stop, then you are free to go up to 3m on your final stop, but are not obligated to up to that depth. The downside to this is on long decompression dives when you are not using 100% O2 to decompress, your TTS will be off by a few minutes.

So why would you want to put 6m as your last deco stop?

Because I would love to make it progressive with a deco stop at a deeper level than a safety stop. In example 6m (deco) > 5/3m (safety).
I know it's all about wording and it won't change much the final result, but it looks more linear to me than having a 3m deco + 5m safety after a shallower deco (!) ..sure I can stop at 6m, but why I have to have that 3m indication?

 

[npole]

Sorry to add a simple question, but, I could not find the answer in the Shearwater manual for the Perdix rec mode. Do I understand correctly that a Perdix, in rec mode, will give you a timed safety stop after fulfilling a deco obligation? Perhaps mistakenly, I have always thought a dive computer would give you a safety stop for a no-stop dive or deco stops if indicated.

Or better, adding the safety stop to the deco if the deco is less than the entiere safety stop.. and at the same level. This is what I would do by "logic", but it does not, it will give you the last deco stop (in example: 3 meters) and as soon it finishes, if will give you a safety stop at 5 meters.

In the OC Rec mode, there are a number of safety stop settings that can be chosen. You can keep them turned off and do your own safety stop as you see fit. You can choose 3, 4, or 5 minutes or you can choose adapt. If adapt is selected, then the computer will assign the best safety stop time based on your dive profile. If you have chosen a 5 minute safety stop, then do a decompression dive in this mode, it will impose a 5 minute safety stop in addition to your deco stops. If you are planning to do a decompression dive, you can turn off this recreational feature. Better yet, use the tech mode which gives divers a lot more control over their decompression diving.

This is not coherent, yesterday I had only 2 minutes deco, if the safety stop were off I would have ended the dive with a 2 minutes stop at 3 meters, versus the usual 5 minutes stop at 5 meters that I would usually done as safety stop (adaptive) with no deco. It looks wrong to me, the safety stop (if enabled) should be there, but it should be subtracted to the time you spent doing your last stop deco as @TBone suggested.

And again, the TEC mode offers a completely different main screen that is unnecessary complex for a REC diver. Honestly this distinction that a REC diver should never hit any deco is plain wrong and a consequence of marketing and business (due to PADI if you hit any deco you're basically died.... unless you buy their TEC courses).

 

[Dave Bevan]

I can't really see what the issue is here?

You said you had two minutes deco but when in the dive did you have that? You are talking like its 1 hours deco. Surely you can see it doesn't matter if you do a 5 minute safety stop at 6m? A 3 minute stop at 4 or a 2min stop at 3m? All ways the deco will disappear. If you want it progressive just do the safety stop at 3m after the deco is gone. As someone said you can do the safety stop anywhere between 6-2m.

The programming of 6m and 3m safety stops for tech is nothing to do with the display more to do with how rough it is and whether you are using 100% O2. In rough conditions 3m can become 1m pretty quickly. Not good if you have 45 minutes to do and a ceiling of 2m. Also if you are using O2 its much safer to be at 6m as it doesn't make any difference.

You could burn 2 minutes deco off simply hanging around at 10m for a while and then do your safety stop.

I think if you are just worried about the fact it is indicating 3m then maybe you need a different computer. Or just get rid of it completely and use a BT and run it in your head

 

[scubadada]

In the OC Rec mode, there are a number of safety stop settings that can be chosen. You can keep them turned off and do your own safety stop as you see fit. You can choose 3, 4, or 5 minutes or you can choose adapt. If adapt is selected, then the computer will assign the best safety stop time based on your dive profile. If you have chosen a 5 minute safety stop, then do a decompression dive in this mode, it will impose a 5 minute safety stop in addition to your deco stops. If you are planning to do a decompression dive, you can turn off this recreational feature. Better yet, use the tech mode which gives divers a lot more control over their decompression diving.

Thank you Lynn, that's exactly what I wanted to know