New diver, looking at Suunto D5

[inquis]

So I don’t think Suunto is especially conservative

For clean dives, RGMB is fairly aggressive, with NDL times comparable to Buhlmann GF x/95 (widely regarded as low conservatism) shallower than 110 ft. However, it does earn that conservative reputation on repetitive dives. Suunto themselves seem to agree, as they implemented changes in this regard. They state:

Suunto has adjusted Suunto Fused™ RGBM to a less conservative direction. The adjusted algorithm – Suunto Fused™ RGBM 2 – allows shorter ascent times on deep air dives and on repetitive dives. On repetitive dives, the change primarily affects Air/Nitrox dives.

The majority of their models employ RGMB (conservative for repetitive diving), which is used in Suunto Vyper Air, Vyper, Cobra, Cobra3, Zoop, D4i, D6i, and older discontinued models like the venerable Mosquito. Fused RGBM2 is used in the D5. Their "Technical RGBM" is yet another algorithm (HelO2 and D9tx models). One really needs to be specific when condemning or praising their offerings.

 

[formernuke]

I have no problem with suunto algorithm, that's personal preference. Heck I have my computers set very conservative.

My issue is the quality, quality control and horrible customer service.

 

[Cheizz]

The conservatism hasn't been a problem for me either. The lock-out is. The entire rationale behind it is too.

 

[Robert H. Diver]

I have no problem with suunto algorithm, that's personal preference. Heck I have my computers set very conservative.

My issue is the quality, quality control and horrible customer service.

The conservatism was never a problem especially with the Eon Core, it was the lockout “function” and customer service.

 

[GreggS]

Yeah, as I said earlier, I never had to call a dive early because my NDL was too low. I was normally one of the last ones to get back on the boat. But after having 2 Suuntos fail, I went another direction. I still have some functioning Suuntos and wouldn't hesitate to use them if my Oceanics failed. But I won't buy another Suunto.

 

[Wibble]

Used to dive open circuit with a Perdix set to GF 50:80 and a Suunto D9tx set to the most "aggressive" setting of -2. The Suunto was always clearing after the Perdix; if there was a fair amount of deco (e.g. deeper 'mix dives) then it could hold me in the water for another 10 minutes after the Perdix had cleared.

I have a pathological hatred of the stupid lockout function on Suuntos.

It didn't help that the user interface was horrendously complex with short and long presses on all buttons; that it arbitrarily miscalculates the MOD of a gas to be shallower; that it refuses to change gas unless you are above the MOD (which is shallower than it should be); as a watch, it's hard to see; and the battery fails just when you want to use it -- the LDS wants £$€ 50 to change it, or change it yourself for $5.

Shearwaters are a dream to use in comparison. I've now got three and looking for a fourth.

I should give the D9tx away but I don't hate anyone that much.

 

[Robert H. Diver]

Love their actual watches though.

 

[shark_za]

The conservatism hasn't been a problem for me either. The lock-out is. The entire rationale behind it is too.

So explain something to me,
If you miss a deco stop and go over the gradient for the profile.
How do other computers handle this?
Treat it as in water recomression? Just carry on like it has not calculated a problem and tell you to get below a ceiling?

 

[Cheizz]

Most computers - as I understand it - calculate a new solution from the point at which you are. If that's not the original plan, they give you a new plan, basically. Suunto tosses the towel instead, leaving you hanging in a deco situation without any deco information or recalculated plan. That is not a 'safety feature' as they call it. That is giving up when you most need that info and a new plan.

Punishing me for not doing a deco stop? Reprimand me afterward, when I'm on dry land safe and sound. Penalize me with a 48-hour lock-out if you want. But not mid-dive, please.

My personal issue with my Suunto (EON Core) was a lock-out mid-dive for no apparent reason. I was not doing a deco dive, I was well within my NDL. It just said 'locked'. Or rather: 'good luck, I'm off'.

 

[KenGordon]

So explain something to me,
If you miss a deco stop and go over the gradient for the profile.
How do other computers handle this?
Treat it as in water recomression? Just carry on like it has not calculated a problem and tell you to get below a ceiling?

For the dissolved gas models, which these computers all are really, there are two things happening.

The first is constantly calculating the actual gas tensions in the model’s compartments. The second is comparing those gas tensions with some limit.

If you go over the limit then you can carry on calculating the actual tensions (1) eventually though the tensions will drop below the limit (as the diver off gases) and the ceiling will be above (2) the ambient again. It a choice about what to do, lock people out, like Suunto, or not, like Shearwater.