RGBM Algorithm for Technical Diving

[KenGordon]

Read the manual and dive the computer and you can soon see how it behaves. Probably less guessing than reading some fortran and expecting to know what it will do.

If you skip that safety stop then it wants an extended surface interval. If you ignore that you get a shorter NDL on the next dive.

But of course you plan your dives so know what your surface interval will be and your plan for the second dive takes that into account. You can do that for the entire duration of the 'mission'. You need a laptop for that unfortunately, whereas for the GF computers multideco on an iPad is more handy. For conservative gas planning/checking on the boat though multi deco will do.


The Eon Steel and DX have another marketing term and slightly different behaviour.

The single gas and nitrox only computers seem to behave just like the helo2 except they do not insert the deep stops and the TTS treatment of the optional safety stop is different.

I use a Zoop as a backup to the helo2. They track ceiling until I get onto a shallow deco mix when the rate of off gassing is so different the Zoop falls behind.

I don't know where the 'emergency deco only' thing comes from. The Zoop manual does not say that or treat deco in any kind of dumbed down way. If doing single gas twinset deco diving a Zoop is a perfectly fine computer for deco.

I agree that the deep stops in the 'technical' suuntos do seem to be a marketing thing really.

 

[DevonDiver]

You keep saying 'NDL'.... but this is a technical diving thread.

What we need to know is whether the computer could secretly amend the algorithm, in comparison with planning software..... thus leading g to a critical discrepancy causing the gas and O2 CNS/OTU plans to be breached.

You can plan a series of decompression dives on a laptop, including surface intervals. But reach up too quickly to scratch your head... trigger an ascent violation... all current and subsequent plans are now voided because the Suunto has put an algorithmic 'dunce cap' on you and sent you to sit in the corner for a while...

 

[KenGordon]

Is that a special sort of secret indicated by a warning triangle on the computer?

Also, from the manual.

"The PC software takes the residual inert gas of the previous dives into consideration when the dive profile is downloaded from the dive computer. "

So maybe it takes the previous violations into account too.

Doing actual dives on the Helo2 I find that I get out on time. Looking back at plans vs execution I see that the deco is over when the plan predicted. In a 90 minute dive the odd minute of extra stop due to some ascent violation on the previous dives does not seem like a significant issue. You will have gas for failures etc in any case.

If you dived these 'technical' dives on these computers I am sure you would soon become quite comfortable with how they pan out.

I have not been surprised. I don't follow a plan and then arrive at 6m with more time showing than I expect.