Mares Icon HD - deco stop on 3m

[DevonDiver]

Any algorithm not set to 3m incremental stops. In particular any computer presenting as continuous decompression such as a Suunto. The stops are not constrained to 3m intervals but go up as you off gas. You can try this by comparing the schedule for the same bottom time in multideco (for an example) given 3m stop intervals and 1m (or even less). You will also notice the total run time is significantly different.

Ken, what dive computers specifically don't present deco stops in 3m increments?

 

[KenGordon]

Ken, what dive computers specifically don't present deco stops in 3m increments?

The Zoop for one. I remember distinctly trying to keep it from bending on my BSAC Explorer Mixed Gas. It was showing a 7m ceiling when we finally moved from the 9m trapeze to the 6m one. Suunto even make a point of this in their marketing materials - see the fourth page of http://ns.suunto.com/pdf/Suunto_RGBM.pdf. The shallowest ceiling it will show is 3m though.

 

[DevonDiver]

The Zoop for one. I remember distinctly trying to keep it from bending on my BSAC Explorer Mixed Gas. It was showing a 7m ceiling when we finally moved from the 9m trapeze to the 6m one. Suunto even make a point of this in their marketing materials - see the fourth page of http://ns.suunto.com/pdf/Suunto_RGBM.pdf. The shallowest ceiling it will show is 3m though.

Well.... that's certainly a cunning marketing slant for not providing your customers with Gradient Factor control... LMAO

I'm guessing that the Suunto 'Tech' computers don't have this "benefit"?

 

[KenGordon]

Well.... that's certainly a cunning marketing slant for not providing your customers with Gradient Factor control... LMAO

I'm guessing that the Suunto 'Tech' computers don't have this "benefit"?

I had a helo2 on the other wrist. It knew what gases I had been on so wasn't so keen to keep us deep, however it had had stops at 13m as I recall. It is not so engraved on my mind as the Zoop, we had skills at 6 to do next so if I had coaxed it there I would probably have avoided bending it at all.

GF control? Pah! Why not let me pick my own m-values? Time to get an OSTC...

Edit...

Googling turns up this http://ns.suunto.com/pdf/Suunto_Dive_Fused_RGBM_brochure_EN.pdf which confirms it is still in the EON and DX which are 'technical'.

Here is a question. If you have 10 minutes of stops at 6 and 20 minutes at 3 but are not prepared to go to 3 for sea conditions or whatever would you rather the computer ticked down the depth so you can move up to 5 or 4.5 t the earliest opportunity or keep you at 6 until you can move to 3?

 

[DevonDiver]

So, basically... people will be coming up at their m-value? No conservatism?

Unless they've got the knowledge to apply their own rough GF Hi/Lo calculations on-the-fly, in respect to where they decide to ascend in the zone?

 

[Ihtiander]

The answer I tried to get here is - Yes, it is Mares algorithm which send diver to make deco-stop exactly on 3m depth, but...... new firmware 5.0 will come soon and there will be option to choose depth for deco-stop between 3, 4,5 and 6m.

 

[KenGordon]

So, basically... people will be coming up at their m-value? No conservatism?

Unless they've got the knowledge to apply their own rough GF Hi/Lo calculations on-the-fly, in respect to where they decide to ascend in the zone?

I am taking the piss out of GF values as they are voodoo. If the punter gets to pick those why not the underlying m values? They are all just numbers after all, a bit higher or a bit lower what does it all mean? Two knobs or 18 knobs? Which is better?

Back to sensible... The ceiling applies to the current gf as interpolated between the low and high gf you are running, so it has that conservatism applied already, however some other delay (maybe addition conservatism) is applied by the stops being at fixed depths. I would rather know my actual ceiling than just that is is between Xm and X+3m. I always plan a 6m last stop in the uk for gas planning in case I cannot go shallower, but I will go shallower if conditions allow on the day.

 

[KenGordon]

The answer I tried to get here is - Yes, it is Mares algorithm which send diver to make deco-stop exactly on 3m depth, but...... new firmware 5.0 will come soon and there will be option to choose depth for deco-stop between 3, 4,5 and 6m.

So it is a bug? It looks like the manual describes a range. I will read the manual again.

This bit:
DECO stops are generated progressively as you stay at depth beyond the no deco time. DECO stops are MANDATORY As you approach the depth of a stop, the duration of the stop

is gradually reduced. The duration itself is always shown in minutes, and is calculated as a function of the pressure gradient achieved at the stop depth itself. Hence the farther you are from the exact depth of the stop, the longer it will take for each minute to tick off.

Sounds like usual computer behaviour and nicely describes "Suunto minutes".

Are you saying you have to be AT the stop depth for it to count? Or are they going to have a firmware update to allow the last stop depth to be chosen to improve the accuracy of the time to surface if not intending to go as shallow as 3 for the last stop?

 

[CuzzA]

While I haven't used the deco mode on the Icon, in the class I linked earlier it explains what happens. Perhaps @DiveNav can add some further information, but basically once you enter deco mode the algorithm will create all of your stops and times available to view on the Icon screen. In the example dive they used in the class was a 20' stop for 1 minute and your final stop at 10' for 6 minutes. They point out that since the computer is constantly calculating, the stop depth and times may change depending on the ascent. In the example, the 20' stop was satisfied during the ascent so the next stop was adjusted to 10' for 8 minutes. Once you are within 10' of the stop depth ceiling the deco timer will begin. You must hold the stop within 10' below the ceiling. So, In other words you do not need to be exactly at the stop depth, instead you need to be within a 10'/3m range.

In the case of the OP, he could have completed the deco stop at 5m and the Icon should not have told him to ascend any higher. If it did, then he may need to send the computer in for service or perhaps he's running an old firmware. I don't think that would be a universal bug, otherwise @DiveNav would have presented it that way in the class. Of course, since I have not entered deco mode on my Icon I can't independently confirm.

 

[Kharon]

... Furthermore, I don't believe the Icon is what we would categorize as a technical diving computer.

I don't remember anyone saying it was/is. Methinks, too many tech elitists for a simple, honest question. Much too much assuming. Just M2C.