Shearwater Perdix AI

[Marie13]

I spent last night going through the Rec mode manual. Holy cow, is the interface light years better than that on my Geo 2.0 (which will be my backup), which required an online class for me to figure out!

ETA: setting up AI took all of five minutes, including removing port plugs and installing transmitters on first stages.

 

[MomZo]

Hi.

I am thinking about changing my Suunto Zoop for a Shearwater Perdix. The main reason is that my Zoop is way too conservative during repetitive dives, and even more if I dive few days in a row.

After a first dive, I have noticed that my Zoop always gives me the lowest NDL compared to my buddy computers (other brand), no matter the depth. Thus, I am always the one asking to go shallower to not enter mandatory decompression stops. Moreover, the Zoop has a pivot value at 10 meters which makes that you can have a very low NDL when you are at 12 meters (for example), and it goes up to 45 minutes NDL when you go shallower than 10 meters (like 9.5 meters) It is all or nothing, not proportional.

I would like to know how is the Perdix behaviour in term of NDL, for repetitive dives, compared to Suunto computers (if set to OC REC with medium or low GF conservatism) ?
Would the Perdix give me more NDL than the Zoop during repetitive dives?

Thank you for your answer.

 

[Scared Silly]

In general you will find that that the Suunto RGBM implementation with give you less NDL time with some profiles, namely multiple sawtooth profiles. The Shearwater is more reasonable with those profiles as are other computers. I would certainly look at the Shearwaters but also other computers which might serve your needs just as well without the expense. And this comes someone who owns Shearwater computers.

 

[MomZo]

In general you will find that that the Suunto RGBM implementation with give you less NDL time with some profiles, namely multiple sawtooth profiles. The Shearwater is more reasonable with those profiles as are other computers. I would certainly look at the Shearwaters but also other computers which might serve your needs just as well without the expense. And this comes someone who owns Shearwater computers.

Thanks for the answer. I don't need a specific sawtooth or rapid ascent profile to have a lower NDL with the Zoop, it is just very conservative while doing repetitive dives.
I know I could go with DSAT algorithm to get a more liberal computer, but I would rather going with Buhlmann with GF. So many people are recommending the Perdix for the readibility, the efficiency and the reliability, that is why I might invest in this baby. After all, we don't buy a dive computer everyday.

 

[Lorenzoid]

I used to have a Suunto, and I never perceived it as being "way too conservative" over, say, two or three repetitive dives compared to diving companions' computers. However, I agree that for a greater number of repetitive dives per day, and for multiple consecutive days of such diving, the conservatism gap between Suunto and others widens considerably.

You can't predict very well how the Suunto RGBM algorithm will weight those multiple days of repetitive diving. Buhlmann is more straightforward/transparent.

 

[MomZo]

So that means the Perdix won't be as conservative as the Zoop during multiple consecutive diving days? That's the only thing I want to know.

 

[Pelagicsal]

No. The Perdix will not be nearly so conservative as the Zoop.

 

[dbnewton]

I have a Suunto gekko I keep as backup and Searwater Perdix as primary. I have had the Gekko demand deco stop and Perdix not. I have never had the other way.

Now that is only my experience all based on 2-4 dive per day nitrox OC rec.

 

[MomZo]

Based on 2016 ScubaLab testing results, it is obvious that Suunto RGBM allows lower NDL time than Buhlmann GF algorithm while doing repetitive dives (but not for the first dive)
Thank you for pointing me in that direction as it was exactly the kind of data I was interested in.
I am about to buy a Perdix soon and I will set it to OC REC medium conservatism in a first time and compare NDL with my Zoop that I keep in backup.

 

[admikar]

So that means the Perdix won't be as conservative as the Zoop during multiple consecutive diving days? That's the only thing I want to know.

You can make it to be, if you want to. Just play with GF.