computer conservatism?

[padudle]

Suunto are probably the most conservative recreational computers, others less so. To Akimbo's point, better to understand why, they're just a tool.

Tortuga, I have to agree with your assessment about Suunto computers. My experience was with the Suunto Mosquito and I found it made diving on air almost impractical.

I prefer a computer I can be set to medium conservatism. That has worked out for me over quite a few dives. I guess every diver makes that decision when they set the conservatism factor on their dive computer.

---------- Post added June 28th, 2014 at 11:12 PM ----------

Sounds about right. Now what?

Tortuga,

I think I will avoid Suunto computers since they lack a medium conservatism factor setting. I will investigate the Aeris/Oceanic computers since they give you the option to select something less than very conservative.

Also, I noticed that some of the Tech-Rec computers such as the DiveRite Nitek-Q allow you adjust something called a Gradient Factor. I don't really want or need a complicated computer but I will investigate the possibilities there.

Do you have any suggestions for reliable, easy to use computers that let you adjust the safety factor from liberal to conservative?

Pete

 

[Tortuga68]

I have always used Suunto's for my rec diving, the conservatism never bothered me (much, except when I went beyond NDL and 'bent' them). Air to 20m and nitrox to 30m. You can change the conservatism with the Personal setting but really only to make it more conservative since most people dive them on P0 (the least conservative setting). There's always gauge mode (i.e. bottom timer) and cut tables e.g. decoplanner etc. I think they're fine for recreational diving and if you use a less conservative computer you should understand why it is and what that means.

 

[padudle]

The mathematics behind dive computer algorithms is really pretty simple. Manufacturers layer on marketing mumbo jumbo but they all do pretty much the same thing.

The most important difference that affects the diver is relative conservatism. Except for a very few lab tests and word of mouth it is difficult to know in advance whether a dive computer is liberal or conservative.

Really, divers would be much better off if DC manufacturers would publish their algorithms as open source. Then we could compare the different algorithms and safety factors over a number of dive profiles. Obviously, that is never going to happen.

I really admire the quality of design and construction of the Suunto DC's. If they would only offer a medium conservatism factor setting I would gladly dive with them. I don't really want to get into the off-label techniques that can be used to make a computer operate in a less conservative mode.

So, I will probably buy an Aeris or Oceanic dive computer. Then I will fiddle with the conservativeness setting until it matches my old computer. Decompression sickness will not be what kills me.

 

[j2s]

Suunto are probably the most conservative recreational computers, others less so. To Akimbo's point, better to understand why, they're just a tool.

......Exactly, they are just a tool....Look into V-Planner, 30 day free trial, I think it's still just $68.00 to load it on three computers and free updates......You can set your dive plan as conservative or as radical as you want.....Good for OC, mixed gas, CCR etc......A whole lot easier to use and wondering what a computer (no matter what the brand) may or may not be !!!!......

 

[MB NZ]

Just to add to the discussion, the algorithm found on the Hel02 is different to the recreational computers. The P-2 setting is pretty aggressive if that's your thing. A bit too much for my tastes.

 

[kr2y5]

So, I will probably buy an Aeris or Oceanic dive computer. Then I will fiddle with the conservativeness setting until it matches my old computer.

Hmmm, you have recently posted about your friend fiddling with % oxygen to match the conservatism of an old computer... now, it appears that incidentally, you also happen to have an old computer that needs to be matched against with respect to conservatism with a newly purchased computer. If you are determined to go down this route, you would be well advised to buy a computer that runs gradient factors and allows you to get arbitrarily close to pure Buhlmann, which is generally considered way too aggressive. At least, you will have the option to get close to, and well past, the limits of what is reasonable for you, by modifying the parameter settings of your computer, while using a proper algorithm, and without cheating it in any way to produce distorted results. Petrel definitely fits the criteria, and there are probably several others...

With respect to what is more conservative, the question is not well-defined. On more than one occasion, my Petrel on the 30/70 default setting would be giving me much more conservative NDL than a Suunto that I carry as a backup, but only on the first dive of the two... then on the second dive, Petrel would give me a small deco that clears quickly, while Suunto would be getting bent. So, at least a few data points suggest that there is no clear ordering in terms of conservatism, it depends on the circumstances.

 

[rivers]

i wouldn't start messing around with gradient factors unless you have an idea of what you're doing. just my 2p...

 

[padudle]

Thanks for all the well thought out responses to this thread. It has been a lot of fun.