Vison backup Computer

Megabites

So I just read through a very lengthy thread about someone getting bent using an EVO. That thread got way off topic and I was disappointed to it missing some answers that someone like me looking into eCCR could use. Mainly if the Vison computer is not adaquate for multiday diving (not saying it is or isn't) then what computer would be a good backup to it?

To avoid one potential sidebar let's assume that the dive(s) are unplanned and that we want our electronics to maximize BT.

I am most interested in what tools (other than the one between your ears) can be integrated into the system to make for a safer dive?

One key point that was pointed out was padding deco stops and another about depth and times of stops actually confusing the computer. Is there a computer that does a better job of planning stops or are they all the same? Is this something a computer could never do properly or at least better then they do now?

Don't get me wrong I don't think the electronics should do all the work. I would just like to know what the best solution or system is.

Mega

ccr_ada

?? well yes it did go of topic didn't it

(i havent run the tables they are all
hyperthetical ok but you can if you want i know someone will )

what im trying to say is if the vision conputor was
detatched it may be better i think (what if my vision went down on a gas weeks diving but someone had a spar head then it would carry on as nothing had happend )

for rob just my 2p
lets have less plz i do like the smiles they are funny

ada

decoweenie

May I suggest a different summary of that thread to... "someone getting bent while happened to be using an EVO"!

I don't think there was any conclusive evidence that the bent was caused by the EVO or Vision software -- unless I misread the information given on the thread.

If he was diving a different unit, I don't think the end result would have changed.

__________________
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CCR900

For a while I dived the Vision with a VR3 straped to the other arm (fixed set point). I dived 15/85 on the Vision and 0 Conserv. on the VR3. I would put the VR3 into "Use Tables" mode (I prefer a slow ascent to deep stops (I pass them by) - more with the mackrel affect than anything else) and get out of the water using the Vision and noted that VR3 would clear about 1 or 2 nminutes after the Vision.

Famous last words but neither of the softwares have got me bent.

I know people that have bent themselves at 20m on a 30' dive on EAN32 and other dovers that have blown very risky tables and felt fine.

Unlike computers we as users don't come out of boxes so what is good for me might be really bad for others. Probably best to take it slow and reduce conservatism until you feel the balance between safety and getting cold on deco is reached.

F

Mackeral Affect - The habit of divers to collect around one given depth/point on the upline due to the fact the computer is telling them that's where they should be.

Megabites

First to address Decoweenie. I have no intension of placing any blame on any product. In fact just the opposite. I am looking for harware redundancy that makes sense. Kinda like having a second chute when parachuting. Ya one works just fine until it has a problem. We all realize that we are always at risk reguardless of how we deco. I am also not interested in that debate in this thread.

So back to topic. Is the VR3 the best backup? How about the HS Explorer? I see they have a model with O2 input now? Are there any others? More important do these do the job we are asking them to do? Could they be better and if so how? Do they allow for a setpoint change or does that matter if they are reading o2 via sensor?

Thanks for the feed back.

Mega

01RMB

I have been going through the same decision process. The options are:-

• Spend the money on a VR3 (doesn't even have to plugged into the loop - just assume constant set point of 1.3)
• Use another constant PO2 computer such as the Cochran or the Explorer
• Find another constant PO2 computer such as the yet to be sold Heliox
• Use tables and a bottom timer

For the moment I have stayed with the last option - for me, none of the computers seem to quite provide the simple interface I want, at the price I want to pay or match the deco profile I get with the adjustable GF settings of the vision computer which I use as the primary computer.

I plan the dives using GAP and have put together a number of set prepared tables for various depths and times. As long as the profile and run time on the tables and the vision computer are similar I just use the vision computer for deco. If anything were to look odd or if the computer were to fail I would go to the tables and bottom timer.

I still keep looking at one of the first three options as a better backup though.

__________________
Cheers
Rod

Tom F.

I think it is very important to find out what kind of algorytme you want in your back-up computer. Do you want Bühlmann with GF like your Vision
or do you want RGBM or VPM-B.

Personally I want to have my backup in a different algorytme, than my Vision and since I really like VPM-B profiles I only have two option at present.

1) VR3, With VPM
2) Tables and Bottom timer.

Do to the price I use the 2. option

Tom F.

decoweenie

Trust me, my intention wasn't to debate but just to clarify.

As others have pointed out, the Vision deco uses GF algorithm. So if you want to have a back up computer using the same algorithm, there are/will be only 2 options:

1. Shearwater
2. Heliox

AFAIK, the status of the aforementioned are:

• Shearwater new hardware/software is complete and Bruce is waiting for the case. Bruce will have different options for connecting to the sensor, or to replace the existing displays depending on the unit.
• Heliox is also waiting for the case.

Of course, no one knows but I think both will be ready about the same timeframe (this Spring). Contact them directly for additional information...

If you want similar profiles, use one of the computers with RGBM or VPM algorithms such as:

1. VR-3 with VPM/B option
2. HS Explorer (with RGBM)

or one that (supposedly) produces deep-stop profile such as:

1. Cochran EMC-20H

Hammerhead uses GF algorithm, but you can't have it as an independent computer.

However, doing deco dives on a CCR requires more than just a redundant deco computer since you will also need to plan for adequate OC-bail-out. So most people also carry a back-up table with the OC-bail-out requirement computed as the last source back-up.

__________________
"...after a while you get bored offering advice to a bull that like to keep butting the fence with its head rather than walking through the open gate..."

- Rebreather World PM

Beanie

Yes the VR3 allows two set points, you can change them underwater anyway.
I have mine set to 0.7 and 1.25, if i decide I want to run my deco at 1.5 I can raise it.

Can't say alot about the explorer other than I don't like the buttons.

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Beanie
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caveseeker7

The Explorer allows for multiple setpoints, too.

Another option coming our way is the Shearwater Deco Computer from Shearwater Research. Bruce Partridge is a member here if you want to inquire about the current status. There is info in the Shearwater DEMA Sneak-Preview and pictures in the gallery, though remember the computer picturerd is a prototype.

__________________
Cheers
Stefan


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