Is the algorithm used by the Oceanic DataTrans still valid today?

[DareDevil]

Hello All,

I am still diving with my trusty Oceanic DataTrans (yes I know it is old...).

Despite a number of dives, I haven't yet found a suitable replacement, since I am accustomed to its big display (lots of information immediately available without the need to flipping pages). I have tried for a while the Aladin Air Z Nitrox, but at the end I didn't like it.

However, the computer is quite old and meanwhile the studies behind tissue saturation have advanced a bit.

My question is simple: is the DataTrans algorithm still valid nowadays, or it would be safer to discard it and replace with another computer?

Any help appreciated.

DareDevil

 

[Randy43068]

Hello All,

I am still diving with my trusty Oceanic DataTrans (yes I know it is old...).

Despite a number of dives, I haven't yet found a suitable replacement, since I am accustomed to its big display (lots of information immediately available without the need to flipping pages). I have tried for a while the Aladin Air Z Nitrox, but at the end I didn't like it.

However, the computer is quite old and meanwhile the studies behind tissue saturation have advanced a bit.

My question is simple: is the DataTrans algorithm still valid nowadays, or it would be safer to discard it and replace with another computer?

Any help appreciated.

DareDevil

If it hasn't bent you then it's still good to go.

 

[DareDevil]

If it hasn't bent you then it's still good to go.

Fair enough... But I think that DCS is more probabilistic than deterministic, so the fact I am still (relatively) sane doesn't imply I will always be

DareDevil

 

[gcbryan]

A better answer might be that you will be fine using your current albeit older computer since very little has changed in decompression theory land since Haldane.

Most computers today still are based on Buhlmann algorithms which I'm sure your computer is based on.

 

[redacted]

I also dive older Oceanic computers - in my case the Data plus. One of my buddies dives newer Oceanic computers and we were observing some differences in dive time remaining data with mine being somewhat more conservative. After questioning Oceanic and then doing a little experimenting, we concluded that the nitrogen related algorithms are unchanged but there has been an update in the oxygen algorithms that was causing the difference.

 

[DareDevil]

Thanks - that's what I was looking for.

I'll keep the DataTrans then... One day or another it will stop working and I will have to find a replacement

DareDevil

 

[teknitroxdiver]

It's no less valid than it was when you bought it.

 

[Funky556]

If it hasn't bent you then it's still good to go.

+1 ... I'll drink to that!

 

[gcbryan]

I also dive older Oceanic computers - in my case the Data plus. One of my buddies dives newer Oceanic computers and we were observing some differences in dive time remaining data with mine being somewhat more conservative. After questioning Oceanic and then doing a little experimenting, we concluded that the nitrogen related algorithms are unchanged but there has been an update in the oxygen algorithms that was causing the difference.

This doesn't make sense to me. I can see making the MOD more conservative and therefore not matching his but dive time remaining is based on nitrogen loading. I can think of no way making any changes to oxygen calculations would affect this.

Can you provide more detail? Was this after 5 dives a day 10 day diving vacation dives where you were coming up against the oxygen clock or something?

 

[redacted]

This doesn't make sense to me. I can see making the MOD more conservative and therefore not matching his but dive time remaining is based on nitrogen loading. I can think of no way making any changes to oxygen calculations would affect this.

Can you provide more detail? Was this after 5 dives a day 10 day diving vacation dives where you were coming up again the oxygen clock?

PDPS dive planning time limit ("NDL") is based on both nitrogen and cumulative O2 loading. It was not a MOD issue - my computer is unsettable at 1.6 and his was programmed also at 1.6. We ran our test on a 3-day trip to the Flower Gardens. 1st day 5 dives & next day 4; all in the 80 to 100 ft range on 32%. We were diving HP 100s with fairly good SACs so all dives were "NDL" limited resulting in fairly high loadings. By the 2nd day, my computer was starting to show shorter times at deeper depths for PDPS dive planning, always limited by O2 accumulation. But you are right it did not effect the dive time remaining display during the dive, the difference only showed up in the PDPS mode after multiple dives and quite a bit of dive time. After the first day, we both had to pay closer attention to the cummulative O2 load than to the N2 load. The graph resolutions are quite different in old vs new Oceanic computers so we could not directly compare cumulative O2 status during a dive.