Perdix, Deco plan (real time)

[npole]

@npole. Perdix Dive Planner on the surface allows you to calculate what NDL would be based on SIT, average depth and time for next dive. And, a deco schedule based on that input from the user. Once you start the dive it will give you acutal on-the-fly info on what actual stop schedule is as the dive progresses. Hope that helps.

Thanks, I figured it out from the previous post. It wasn't mentioned (or I couldn't figure it out) from the manual, so I never checked that page during the dive. I'll try it next time.

 

[JohnnyC]

I gotta say, Shearwater’s TTS feature changed my outlook on executing a dive plan.

For the foreseeable future I think I’ll continue to use a main plan with four contingency plans all derived from V-Planner and transcribed to a wrist slate along with a BT.

But man, oh, man....the Shearwater planner and TTS make it a challenge to still regard my slate as the primary and my computer as a back up. I think as long as I don’t abuse the TTS feature and blow past the contingency plans on my slate, it’s a great back up that will keep me from getting hit.

I don’t think I’ll get another Perdix anytime soon but I wouldn’t be opposed to a primary and backup Perdix and skipping the slate all together.

Plus, going double Perdix will allow me to get in touch with my inner Wonder Woman with the double wristband look.

Not even the GUE wünderkind dive with their computers as a backup anymore. Your computer actually knows what's going on, it's not just a plan based on a perfect set of assumptions. Tables are great if your computer shits the bed, beyond that, they're inherently less accurate than a computer that knows real-time what's going on. It's like driving a car. You can either trust what the manufacturer rates it in mpg and do the math and hope that you were leaning to the highway side of the rating and not the city, or you can use a gas gauge....

If you're relying on your computer to cover those use cases where your tables are busted, you might as well be using your computer as a primary anyway. By all means keep the bt and a set of tables as a backup, but if you're out of scope on your computer, a set of tables isn't going to save you anyway unless you've got a whole set in some wetnotes.

Ditch V-Planner and take advantage of GF99 and SurfGF. Being a luddite has no advantage in this situation.

 

[SJT1961]

Anyone know if shearwater intends to update software for perdix to show surfgf?

 

[rsingler]

Anyone know if shearwater intends to update software for perdix to show surfgf?

Huh?
That was in firmware v65
Subsequent v71 keeps that, plus fixed an error in SAC calcs in the box's Dive Log.
And Shearwater Cloud now lets you graph GF99.

What's your SurfGF and how does it compare to your (Rec) GFHi?

 

[SJT1961]

Thanks. Guess I’m behind on updates.

 

[NothingClever]

You can either trust what the manufacturer rates it in mpg and do the math and hope that you were leaning to the highway side of the rating and not the city, or you can use a gas gauge....

That’s a helpful metaphor.

By all means keep the bt and a set of tables as a backup, but if you're out of scope on your computer, a set of tables isn't going to save you anyway unless you've got a whole set in some wetnotes.

I agree with you. What I meant to communicate was as long as I don’t use the flexibility of the TTS feature to blow past the contingency plans on my slate, then the slate still serves as a good backup if my Perdix were to suddenly fail. I only have 12 dives on my Perdix but it seems like TTS gives me the flexibility to bite off another 10m or 10 minutes if I see something interesting (and have adequate back and deco gas to linger). However, if my contingency plans on my slate are only “next 5m” and “next 5 minutes” then I will have rendered the slate useless as a backup (I think) if I have already surpassed them when my Perdix fails (worst case scenario). I suppose expanding the contingency plans on my slate would be in order so that they serve as a relevant backup to my computer.

This is all very likely moot since the Perdix probably has an exceptionally low failure rate and because I will probably cave in and buy another one.

Ditch V-Planner and take advantage of GF99 and SurfGF. Being a luddite has no advantage in this situation.

I’ll have to explore further how to use those two features. I’ve read the Perdix manual once thoroughly but obviously not well enough. I don’t have access to my desktop, just my Perdix and an iPad. Am I missing something by not having my desktop program? My TDI instructor is a great guy but he didn’t have a Perdix and wanted to ensure I had a grasp on how to use tables and a BT so that’s been my trained reference point.

 

[rsingler]

Am I missing something by not having my desktop program?

IMO, having SubSurface to graph things out visually, on top of the tablet/phone plan in Multi-Deco, is invaluable. Plus, their reserve gas output is superior, as it breaks out ascent gas from problem solving gas at depth.
Switching plans, GF's and times is literally two seconds work.

 

[SJT1961]

+1 Subsurface

 

[npole]

Subsurface struggle to read all the (after dive) logs coming from the Perdix, ie: gas usage (when you're using AI).

PS: we're OT for the topic.

 

[KenGordon]

it seems like TTS gives me the flexibility to bite off another 10m or 10 minutes if I see something interesting (and have adequate back and deco gas to linger). However, if my contingency plans on my slate are only “next 5m” and “next 5 minutes” then I will have rendered the slate useless as a backup (I think) if I have already surpassed them when my Perdix fails (worst case scenario). I suppose expanding the contingency plans on my slate would be in order so that they serve as a relevant backup to my computer.

I might be stating the obvious, but you need a gas plan. Deco you can wait out, but insufficient gas is insufficient gas.