Perdix "Adaptive" Safety Stop - What's the purpose.

[DiveClimbRide]

Change your safety stop mode to "clear cntr" (clear counter). Once you reach safety stop depth or clear your deco, depending on the dive, it will start to count UP and then you can do with that what you will

 

[Blackcrusader]

Change your safety stop mode to "clear cntr" (clear counter). Once you reach safety stop depth or clear your deco, depending on the dive, it will start to count UP and then you can do with that what you will

All that is in the user manual which the OP Maybe needs to download and read. Hopefully his Perdix is also firmware upgraded to the latest version as this is in V65 onwards. There was another thread where this topic was discussed but not as a stand alone subject.

I mainly do recreational diving but have my Perdix in OC Tec mode as I prefer that.

 

[Blackcrusader]

Can anyone explain the point of the adaptive Safety Stop option.
Recently I had a dive to 32m for a total of 34minutes, it was a square profile wreck dive.. This was my first dive of this kind with the Perdrix.

I had an initial Deco Stop at 6m for 2 minutes followed by 3m for 3minutes stop ; my Perdrix is set to Medium conservation, so a 40/85 GF. After the mandatory Deco Stop completion the Perdrix then displayed a 5 minute Safety Stop....
Cheers

My Perdix is setup to do a 5 minute safety stop so even if I clear a deco obligation I still do a 5 minute safety stop. You can change the time and depth in settings. I like to off gas a little longer and I always tell my dive buddy or guide my safety stop is 5 minutes not 3. I once had a guide berate me for doing a 5 minute stop as he assumed I had gone into deco at some point when I hadn't. He did not know the settings I use on my dive computer.

Download the latest manual and update your firmware then read that and use the forums here. I had a lot to learn after going from Sunnto to the Perdix when I first got it V53 was the latest firmware so the DECO Clear and safety stop clear when added minutes after you finish the safety stop are added on in V65. I have seen divers look at my Perdix and wonder why I have an clock counting time after the safety stop is completed so I explain to them the feature of the Shearwater diving computers. It's all good fun learning what this Perdix software can do for you.

 

[Roy_W]

All that is in the user manual which the OP Maybe needs to download and read.

Unfortunately there are 2 manuals and they have differing TTS explanations.... The Tech manual says TTS does not include safety stops, this is normal because safety stops are deactivated.... The "nitrogen" manual, which should read OC REC manual, states that TTS does include all Decos + Safety stops.... Not so easy for the beginner divers to fully understand as this allows at least 2 different answers/paths... I made the mistake of reading the Tech manual first, this is not really a good idea for beginner divers...

One of the major problems, at least for me, is that I dive with others who have many thousands of dives, others who only have a hundred or so like myself and I hear different answers to the same question. Even on this thread we can see the different responses.. Some people don't bother with Safety Stops, for others it's a religion and the manual leaves you to decide for yourself.. And again the manual does not argument why one should use a particular method over another....

This is why I like SB, it allows for multiple, and more importantly many rational arguments, it helps us all to learn.

 

[Roy_W]

My Perdix is setup to do a 5 minute safety stop so even if I clear a deco obligation I still do a 5 minute safety stop. You can change the time and depth in settings. I like to off gas a little longer and I always tell my dive buddy or guide my safety stop is 5 minutes not 3. I once had a guide berate me for doing a 5 minute stop as he assumed I had gone into deco at some point when I hadn't. He did not know the settings I use on my dive computer.

Have you ever had anyone that did not stay with you during your Safety Stop because they wanted to immediately surface after their deco was complete ?

 

[Blackcrusader]

Have you ever had anyone that did not stay with you during your Safety Stop because they wanted to immediately surface after their deco was complete ?

Sometimes but not normally. My dive buddies do a pre dive chat and they know my safety stop is 5 minutes. If we come up directly under the boat I may signal for them to go up but my regular buddies will normally stay with me. Instabuddies I've found tend to clear deco and stay with me and not head to the surface. Maybe that's because it's discussed in the pre dive buddy checks. The other times they might surface ahead is when I give them the signal to get on the boat if we are under it as you can't have us all climb the ladder at the same time.

 

[Don Wallar]

I am trying to get my head around this, does this therefore mean that because I had Safety Stops set to Adaptive and that I had passed 30m, which therefore creates a 5 minutes Safety Stop, that the TTS is simply incorporating my Safety Stop duration as good advice even though not compulsory?

Therefore if I had had the Safety Stop set to OFF, would it just have removed that extra 5 minutes from my final TTS or would it have adjusted and lengthened my Mandatory Deco Stops in order to compensate?

Yes, if you have your Safety Stop setting set to Adapt, then the Perdix will add a 5 min SS if you dive deeper than 100 ft, and a 3 min SS if you don't. This is REGARDLESS of whether it was a deco dive or not. Think of it as additional deco on a deco dive and just normal SS on a non-deco dive. I normally dive in 3 Gas Nx mode and recently did a deco dive to 165 ft. Stops at 30, 20, and 10 ft. After completing all deco stops it then "required" a 5 min SS as well which I gladly performed. The additional 5 min SS was required because I exceeded 100 ft and the fact that my Safety Stop setting is "Adapt". Hope this helps!

 

[rsingler]

Yes, if you have your Safety Stop setting set to Adapt, then the Perdix will add a 5 min SS if you dive deeper than 100 ft, and a 3 min SS if you don't. This is REGARDLESS of whether it was a deco dive or not. Think of it as additional deco on a deco dive and just normal SS on a non-deco dive. I normally dive in 3 Gas Nx mode and recently did a deco dive to 165 ft. Stops at 30, 20, and 10 ft. After completing all deco stops it then "required" a 5 min SS as well which I gladly performed. The additional 5 min SS was required because I exceeded 100 ft and the fact that my Safety Stop setting is "Adapt". Hope this helps!

I'm not sure that's exactly correct.
While the computer DOES automatically switch to a 5- minute safety stop if you exceed 100 feet when set to "adaptive", the computer makes no change to TTS whether or not you have exceeded 100 feet. I note this section from the manual where it shows that TTS does not include the (not mandatory) safety stop:

As you can see in the right hand picture, with a TTS of 1 minute at 30 feet, the computer is NOT counting the gas and time required for your 3 minute safety stop. I suspect that similarly, the computer will not add two minutes to the TTS to account for the 5 minute safety stop. No-stop TTS is merely time to ascend at 30 fpm.

And in deco diving, the safety stop is not factored in at all. When you complete your ten foot stop, you are done for TTS as far as the computer is concerned, except for the time required to transit from 10 feet to the surface.
TTS is merely the total time for a 30fpm ascent, PLUS all required deco stops.

EDIT: I see that this explanation differs from others comments from four years ago. I guess it's time to compare these pics from the manual with the OC Rec explanations. Some folks are saying that the SS is added to the TTS.
I'll believe that when I see it, notwithstanding what was said four years ago.

 

[Tracy]

A safety stop is just that, a safety stop.
It doesn't have anything to do with deco. They are separate things.
I prefer to use them. I ascend at one meter per minutes from my last stop at 6m. Others finish their deco and bolt for the surface. It is up to you how you want to dive.
If you are asking if I think one way is better? Obviously I do or I wouldn't spend the extra time slowly ascending.

 

[Cthippo]

How did this thread from 2021 get necro'd?