Perdix AI - Multi dives - can perdix show time needed for releasing N2??

[MasterMindDiver]

Hello Scuba Board,
recently I got Perdix AI as I am planning to go tec diving in the future .. but in the past I got used to rent Suunto/Cheepo DC while diving..
While renting DCs and doing multi dives per day .. I got used to find a count down timer after finishing every dive for diving safely next dive ... but I can not find something like that in Perdix AI..

I know about the time to fly and Shearwater said that we need to refer to DAN recommendations according to diving tables specially in case of DCS.

what I saw after the first dive in Perdix is tissue loading .. and the N2 bar in the main screen .. got cleared after having surface interval for around 30min.

tried to check the Perdix AI manual but was not able to find any reference for it.
Appreciate if you can share more infromation about how to identify the time needed to stay on the surface while using OC REC mode .
Regards

 

[KenGordon]

The longer you leave before the next dive the longer your NDL will be on that dive. Assuming moderate OW style diving a reasonable rule of thumb is to have an SI of at least an hour. Personally I would rather have two hours but the way resort diving in run you are lucky to get that. The Petrel I have shows 'Surface Time'. Wait for that to get to an hour or more. Because of the exponential rules used in these computers the first hour counts more than the second etc.

There is a planning mode somewhere too. It lets you know what your NDL for a given depth will be if you were to dive immediately. You want to have an SI long enough to enable whatever NDL you need for the second dive. This assumes a square profile though.

 

[Basking Ridge Diver]

Appreciate if you can share more infromation about how to identify the time needed to stay on the surface while using OC REC mode

So - although this is the advanced section - I will take a swing at this. Most divers use an hour as a SIT when vacationing in warm water. In cold water diving 1.5 hour or so is normal.
But you realize that you can dive 10 mins after you surface - right? Your dive time will be severely limited based on your previous depth and time but you are allowed to dive.
So is your question how long should you wait before your next dive? If it is you may want to take AOW and ask that question.

 

[MasterMindDiver]

modifying the title to reflect what I am questioning..

I completely understand what you are saying .. my intention not to ask how do i calculate it ... I can calculate that very well either using diving tables or computer diving planner..

I am questioning if Perdix AI dive computer is having that feature that calculates it based on diving tables and if it can show that information or it is not ? if it can show it .. then i would like to ask how ?

thanks a lot for trying to help me in answering my question

 

[Got2Go]

I'm not aware of any dive computer that will show you a surface interval countdown of when you are OK to go dive again. How would it calculate that? There is no finite threshold to use for a countdown.
Like others have mentioned, 1 hour is suggested, more if possible, as this would give you longer NDLs. Perhaps there are computers that automatically start a 1 hour countdown (based on nothing other than time since dive ended).

Are you, perhaps, thinking about a dive planner, where you can enter depth, and minutes from NOW in order for it to give you a calculated time on how long your NDL would be?

 

[RandomGuy1]

The perdix should show you a surface interval time. It is up to you to decide on how long you want to stay out. If you are asking about it showing a no fly time I don't believe that it does that.

 

[RainPilot]

The Perdix does dive planning where in between dives you can select when you will splash again and then see your NDL for the various depths.

It will also show desat time.

 

[rongoodman]

The tissue loading graph(5 right button pushes from the initial screen) shows the relative amounts of inert gases in each of the 16 compartments in the deco model, with the fastest at the top. After each dive you will see the faster compartments drop quickly, followed by those in the middle. The slow compartments, OTOH, might drop even more slowly, or might gradually increase over several days of multiple dives. It's very interesting to watch on a live aboard trip doing 4-5 dives daily and provides much more detailed information than a simple count-down timer.

 

[MasterMindDiver]

I'm not aware of any dive computer that will show you a surface interval countdown of when you are OK to go dive again.

Are you, perhaps, thinking about a dive planner, where you can enter depth, and minutes from NOW in order for it to give you a calculated time on how long your NDL would be?

No .. that is different that dive planner ..

The perdix should show you a surface interval time. It is up to you to decide on how long you want to stay out. If you are asking about it showing a no fly time I don't believe that it does that.

you are completely right ...

I'm not aware of any dive computer that will show you a surface interval countdown of when you are OK to go dive again. How would it calculate that? There is no finite threshold to use for a countdown.
Like others have mentioned, 1 hour is suggested, more if possible, as this would give you longer NDLs. Perhaps there are computers that automatically start a 1 hour countdown (based on nothing other than time since dive ended).

Are you, perhaps, thinking about a dive planner, where you can enter depth, and minutes from NOW in order for it to give you a calculated time on how long your NDL would be?

that's is different than the dive planner .. as far as I remember D6i was calculating the time needed to release nitrogen exposure.. don't rememeber the other brand names.

 

[MasterMindDiver]

The tissue loading graph(5 right button pushes from the initial screen) shows the relative amounts of inert gases in each of the 16 compartments in the deco model, with the fastest at the top. After each dive you will see the faster compartments drop quickly, followed by those in the middle. The slow compartments, OTOH, might drop even more slowly, or might gradually increase over several days of multiple dives. It's very interesting to watch on a live aboard trip doing 4-5 dives daily and provides much more detailed information than a simple count-down timer.

I heard that tissue loading menu is really interesting from some folks online .. but I am still having that computer for my 3rd day .. still don't know how to understand it .. but for sure will read about it.