Oceanic: Liberal or Conservative??

[UCFDiver85]

Ok, I am a little confused. I just bought an Oceanic VE200 the other day and did 1 dive with it and as of right now I really love it, and loved the price. I've been hearing people call it a liberal computer, and was wondering what that meant? What dictates if a computer is liberal or conservative? Is one better than the other? Any thoughts on my computer?

 

[Charlie99]

UCFDiver85 once bubbled...
I just bought an Oceanic VE200..... I've been hearing people call it a liberal computer, and was wondering what that meant? What dictates if a computer is liberal or conservative? Is one better than the other? Any

Liberal vs. conservative refers to how long and deep you can stay before it indicates that decompression stops are mandatory. A liberal computer has long bottom times before reaching NDL, a conservative computer more quickly goes into the required decompression mode.

Oceanic computers have the same exact limits as the PADI table, but calculate continously for your time and depth.

Many other computers (more "conservative" ones), particularly Suunto computers, will show mandatory decompression requirement while the Oceanics still show a few minute of bottom time remaining before reaching the no-deco limit.

Oceanics and other computers made by Pelagic Pressure Systems have a tissue loading bargraph that gives a good visual indication of tissue loading. If you keep that graph in the green, or at least do safety stops long enough to get it back into the green, then that effectively turns the Oceanic into a conservative (lower bottom time) computer.

.Rodales dive computer review has info on what they call the "freedom vs. risk" tradeoff.

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What is as important, if not more important, than the liberal vs. conservative computer issue, is the actual dive profile (depth-time plot). Doing repeated up and downs and doing fast ascents without safety stops increase your probability of decompression sickness. Doing a 1 minute stop at 1/2 of max depth, then another 1 minute at 30', then 3 minutes at 15' does a lot to reduce the probability of decompression sickness while diving within NDLs

 

[LUBOLD8431]

Uh, ya...what he said...

Charlie, ya nailed it...

Nothing more to add...

 

[100days-a-year]

Oceanics will penalize you heavily for that initial "liberal"phase by acrcruing deco much faster than some other computers.Not that you should use a computer to regularly do deco dives

 

[ColdH20diving]

I use an Oceanic Data pro plus, it's a nice computer and I haven't experienced any problems with it.. it is however, liberal with the Nitrox tables. I like to plan my dives with a max of 1.40ata, my computers calculates to 1.60ata, therefore I calculate my depth/time for any given blend myself.

 

[Charlie99]

ColdH20diving once bubbled...
I use an Oceanic Data pro plus, it's a nice computer and I haven't experienced any problems with it.. it is however, liberal with the Nitrox tables. I like to plan my dives with a max of 1.40ata, my computers calculates to 1.60ata, therefore I calculate my depth/time for any given blend myself.

The Oceanics calculate O2 CNS loading exactly per the NOAA tables as best that I can tell. They do, however, decay that loading with a 90 minute halftime. Strangely, this is an area where the Oceanic is conservative compared to Suunto, which decays away O2 CNS loading at the faster rate of 60 minute halftime.

Does anybody know where these 60 minute and 90 minute CNS clock halftimes come from?

Does anybody know where Pelagic came up with their number for O2 CNS clock above 1.6ppO2? For example, at 2.0ppO2, the Oceanic is has alarms flashing away, but still is calculating CNS clock at around 8%/minute (12.5 minutes = 100% clock).