Mares Puck too conservative?

[Web Monkey]

Is the Puck meant for diving 30m or less? Because I plan to learn to dive deeper that that. I think that was what the issue with the overly conservative computer in the magazine test, the algorythem used simply wasnt meant for diving more than 30m so beyond that depth it started racking up deco time with added deep decos at an unrealistic rate (according to the articles author). Also this conserns me in terms of air usage. If im expected to make very long assents any time I dive a wreck at 35-40m, Im at risk of running out of, or dangerously low on air before surfacing unless I ignore my computer.

A good air-integrated computer will take all required and recommended stops into account when calculating the about of bottom time left. If you have deco stops, these will be figured in, and it should tell you to start your ascent in time to reach the surface with your specified reserve air remaining.

I have no idea if the puck works this way, but it might be something you would want to verify.

In any case, you'll need additional training and equipment if you plan on doing any decompression dives, since going to the surface in an emergency is no longer an option. And unless your buddy has done the correct gas planning, sharing air because you ran out isn't an option either (you can both end up bent or drowned).

You can download the manual for the puck if you want to check it out in detail before purchasing it.

Terry

 

[buddhasummer]

"Suunto Gekko is an ideal choice for sports divers who do not require PC interface interoperability or simulation features." - taken directly from the Suunto website.
Have I missinterprated this? Apart from being unable to download dives to the computer I actually prefere the Gekko. So if I am mistaken, and if from this discussion it turns out that there is no need to spend more for a more sophisticated algorithem, I'll probably buy that instead.

Your rite, I was going to say what my diving intentions are, but I thought the post was already too long;
I want to dive wrecks. Living in the north of england Wreck diving seems to be the best diving experiences here. I particularly want to dive Scappa Bay's wrecks, some of which lie at about 40m.
I have no intention of deep diving for the sake of it, but if the object of the dive lies in deep water (within reason and within my training) I want to be able to dive it.
I also want to be able to make repetative dives, which is my main concern with the Puck. I also want to learn to dive Nitrox, but I am happy that isnt an issue with the puck.
If I am to do tech diving or tri-mix diving in the future I will buy another computer. But I probably wont.

I have looked at many reviews and it seems to be very highly rated everywhere. I have no doubt its a very good computer for the money. but there has been the odd comment on its conservitism.

There is a "Gekko Hack" available on this forum that will allow you top download, in effect it makes the Gekko think its a Vyper, I haven't used this hack but many have and it apparently works fine. Do a search on this forum and you will find the info, if you can find re post and Ill try to find a link. Good luck

 

[Jacky Boy]

There is a "Gekko Hack" available on this forum that will allow you top download, in effect it makes the Gekko think its a Vyper, I haven't used this hack but many have and it apparently works fine. Do a search on this forum and you will find the info, if you can find re post and Ill try to find a link. Good luck

Cheers, I'll look that up. Sounds good aslong as it doesnt void the warrenty.

A good air-integrated computer will take all required and recommended stops into account when calculating the about of bottom time left. If you have deco stops, these will be figured in, and it should tell you to start your ascent in time to reach the surface with your specified reserve air remaining.

I have no idea if the puck works this way, but it might be something you would want to verify.

In any case, you'll need additional training and equipment if you plan on doing any decompression dives, since going to the surface in an emergency is no longer an option. And unless your buddy has done the correct gas planning, sharing air because you ran out isn't an option either (you can both end up bent or drowned).

You can download the manual for the puck if you want to check it out in detail before purchasing it.

Terry

Yeah, the Puck Wirst isnt air integrated. The Puck Air is, but thats a console computer which I dont want.
I certainly wouldnt do deco dives without the necessary equiptment or training.
I did download the manual, havnt finishd reading the main things on it yet. My minds pretty much made up to uy the Puck now anyway. I'll just look through a few more options before I do buy it though.

 

[jd950]

Unfortunately, this is a whole can of worms.

OTOH, people frequently get bent "riding their computers", even though the computer says everything is "OK".

Terry

I am not trying to argue and in fact, dive more conservatively than my computer's "limits," but am curious about your statement and about algorithms in general so I like to read as much as I can on the subject. I have never seen any articles or statistics on this concept of divers getting hurt from "riding their computers."

Could you point me to any literature or articles that talk about this? I actually thought that recreational divers got bent only infrequently and that all computers available today offer a margin of safety within their settings.

Thanks.

 

[Web Monkey]

I am not trying to argue and in fact, dive more conservatively than my computer's "limits," but am curious about your statement and about algorithms in general so I like to read as much as I can on the subject. I have never seen any articles or statistics on this concept of divers getting hurt from "riding their computers."

Could you point me to any literature or articles that talk about this? I actually thought that recreational divers got bent only infrequently and that all computers available today offer a margin of safety within their settings.

Thanks.

You can search the Accidents and Incidents forum here (google actually works better than the SB search)

While they're not washing up on the beaches dead all the time, every now and then someone will pop up with an "undeserved hit" where the computer thought they were fine.

The problem is that the computer's model is fixed and diver physiology and behavior isn't. Hydration, exertion during and after the dive, ascent rate, injuries and a whole bunch of other things all have an effect on decompression.

While the manufacturers try to make the computers conservative enough that divers won't get bent, marketing drives the other side of the problem, where if a computer cuts down bottom time too much, people won't buy it even if it's actually safer.

Terry

 

[LastManOut]

Jacky Boy. You really have to do some more research than just reading catalogues man, no offense. You have to sit down with an Instructor and get them to explain the different models to you. Above is a lot of information as to how not to use a computer. "Hanging it over the side of the boat? Gekko hacking?" FFS... Don't bother.

Do yourself a favour and get yourself a decent computer to start with. Why would you buy a Puck or a Gekko anyway if you want to move into tech diving? That's like learning to drive a Toyota IQ really well when you want to drive a WRX in Rally. If you want to see wrecks at 40m, you're not going to do that within the No Deco Limits, so you're going to need to do Deco Procedures. It takes time to see these things. Diving especially in Scapa Flow is not an easy thing, and takes a decent amount of training.

In terms of algorithms, don't get too strung up on it. All the computers these days are generally based on a Buhlmann algorithm. The RGBM algorithm (although it sounds pretty) is essentially a bit of a clever gimmick - it doesn't really implement a true model, it is a modification of a Haldanean model. It throws more stop time at you if you ascend quickly, or throws a 2 minute pyle-ian "deep stop" in to control fast tissues.

Not only that, if I remember correctly, deco on RGBM model computers like Suunto and Mares sees the computers reverting back to Buhlmann 16 or 8-compartment anyway.

 

[Web Monkey]

Jacky Boy. You really have to do some more research than just reading catalogues man, no offense. You have to sit down with an Instructor and get them to explain the different models to you. Above is a lot of information as to how not to use a computer. "Hanging it over the side of the boat? Gekko hacking?" FFS... Don't bother.

Do yourself a favour and get yourself a decent computer to start with. Why would you buy a Puck or a Gekko anyway if you want to move into tech diving?

In fact, for tech diving, a computer might not even be the right thing to get at all.

I have two computers, one is expensive (SmartCom) and the other is very expensive (Galileo), but for any technical diving, especially any multi-gas deco dives, I use vPlanner, print the dive plan, stick it on my wrist slate and set the Smartcom for gauge mode (time and depth).

There isn't a single dive computer I'd trust to plan the dive on-the-fly. I trust the Galileo to be able to figure deco stops if I screw up, but it's not something I'm comfortable relying on in non-emergency situations.

And even more important than the hardware is a really good buddy you've trained with. A good buddy will verify gas switches, maintain enough reserve so you don't die if you run OOA, and generally keep an eye on you for problems and "I'm stupid" moments.

Terry

 

[LastManOut]

Terry, I use vPlanner too, I'm just not rich enough to get a Liquivision X1 yet, which I bet you would trust to plan to dive on the fly as it runs V-Planner Live. Admittedly, it doesn't have a heart rate monitor, but hey you can't have everything right...

And "IF you run out of air?"... don't you mean "if you have a lost gas scenario"?

-- Nemo

 

[Web Monkey]

Terry, I use vPlanner too, I'm just not rich enough to get a Liquivision X1 yet, which I bet you would trust to plan to dive on the fly as it runs V-Planner Live. Admittedly, it doesn't have a heart rate monitor, but hey you can't have everything right...

Since I write software, I'm very skeptical of any embedded systems that might be able to hurt or kill me. I know they exist, but they don't make me happy.

A pre-generated, printed dive plan makes me much calmer, since I know that the wrist slate won't crash or say ERR or just hang at some inconvenient moment, and I've had a chance to look at it first, and give it a sanity check.

All that a printed plan requires is a working watch and depth gauge, and if mine fails, my buddy has them also.

And "IF you run out of air?"... don't you mean "if you have a lost gas scenario"?

It was close enough to describe the situation.

Terry

 

[LastManOut]

Terry,

Sorry mate, wasn't trying to sound like a jacka--. I was thinking also that maybe the HW Open Source computer is for you then, you can program it to your heart's content!

-- Nemo