Are Suuntos really more conservative for rec diving?

[Xoom]

I’ve read through quite a few fascinating threads debating the merits of various decompression models, particularly as it relates to Tec diving. From these, I see a lot of hesitation (to say the least) about using Suunto computers and bubble models.

My question is from a recreational perspective, all these algorithms seem to work, mostly. Suunto seems to penalize rapid ascents, multi-day diving, shorter surface intervals, etc. with less NDL time. To my ears, this does make intuitive sense, if one wishes to be conservative as I do.

However, isn’t it true that any dive computer penalizes these actions too, in the form of shorter NDL times? If you have a short surface interval, for example, your tissues have less time to rid themselves of Nitrogen.

I appreciate any information or advice on the above, as I am looking to get a new dive computer, prefer to be conservative, and am thinking of a Suunto or Shearwater. Thanks!

 

[ajduplessis]

Suunto’s generally speaking is more conservative that other DC’s IMO but that is not a bad thing.

The Shearwater products are fantastic and allows you the freedom to choose the level of conservatism. Either computer will work fine, its down to what you prefer/like.

I have used and enjoyed both and settled on Shearwater Petrel. The new SW Teric is great but the frequent charging required is not good IMO.

 

[Streydog]

I have over 100 dives over the last couple years using a Vyper Novo with a Geo 2.0 as a back up. The Geo always shows longer NDL but I have not had to cut dives short due to Vyper. Using EAN helps quite a bit though.

 

[Edward3c]

I’ve read through quite a few fascinating threads debating the merits of various decompression models, particularly as it relates to Tec diving. From these, I see a lot of hesitation (to say the least) about using Suunto computers and bubble models.

My question is from a recreational perspective, all these algorithms seem to work, mostly. Suunto seems to penalize rapid ascents, multi-day diving, shorter surface intervals, etc. with less NDL time. To my ears, this does make intuitive sense, if one wishes to be conservative as I do.

However, isn’t it true that any dive computer penalizes these actions too, in the form of shorter NDL times? If you have a short surface interval, for example, your tissues have less time to rid themselves of Nitrogen.

I appreciate any information or advice on the above, as I am looking to get a new dive computer, prefer to be conservative, and am thinking of a Suunto or Shearwater. Thanks!

Deco theory, is just that theory. Select the model your happy with and go diving.

Personally, I’ve never had to cut a dive short because of Suunto’s algorithms. It’s usually the amount of gas I can carry that limits a dive.

 

[Centrals]

Read the limitation on RGBM and make sure not to violate any of them.
My brother has never complaint his Gekko.

 

[admikar]

My dive buddy have a Suunto (don't know which model). I dive Perdix with GF 50/80. On every first dive of the day, I would go to deco faster than he does. Second dive, reverse.

 

[Lorenzoid]

"Penalize" is a loaded word. In computing NDLs the Suunto RGBM algorithm gives more weight than other computers (some giving zero extra weight) to events such as short surface interval, rapid ascent, reverse profile, sawtooth profile (I think), and doing multiple dives per day for multiple days. Whether this is for your benefit or a "penalty" depends on whether you are persuaded that these events increase the risk of DCS. Some clearly do, such as a short surface interval, some may, such a rapid ascent, and some seem fairly well discredited in the deco physiology literature these days.

My story is that I chose a Suunto as my first dive computer--maybe 15 years ago--because I liked the idea that it might be the most conservative computer. Keep in mind that Suuntos are used by divemasters all over the world who lead groups of divers on classic resort and liveaboard types of dives around coral reefs and benign wrecks. As that was the kind of diver I saw myself as, a Suunto sounded just fine for me. I bought a D6, which still works fine all these years later, bought a Cobra for my wife in 2009 when I got married, and after that bought a Zoop--all of which served us just fine for that kind of diving. We never felt that dives were not long enough for us to enjoy. We always surfaced within minutes of most other divers in our group, sometimes maybe five or six minutes earlier than some others on the 3rd or 4th dive of the day, but to me that's insignificant in the context of a week-long dive trip. With so many divemasters using Suuntos, we often surfaced when the DM did. I'm a recreational diver, there to relax and have fun--I don't need hour-long dives every single dive, four times a day, for a week.

Fast forward to today. About five or six years ago I decided to learn more about diving--more deco theory, more skills, and more everything--with the simple goal of becoming a more skilled, more knowledgeable, safer diver. I came to the realization that it doesn't matter what computer I'm using. If I want to be conservative, I can dive more conservatively--start going shallower well before no-deco time runs out, lengthen my safety stop, ascend more slowly near the surface, etc.--without a computer screen telling me how to do that. Although I now primarily dive a Shearwater, I could still do my vacation diving just fine with a Suunto. The Shearwater gives me more flexibility, and at this juncture in my diving--with the knowledge, skill, and discipline I think I have--I can dive just as conservatively with the Shearwater as with the Suunto if I choose to.

 

[AJ]

The real question is: do you want your computer to tell you what to do or vice versa? There's no wrong or right, just a choice you will have to make. If you want your computer to tell you what to do, about every computer is fine. Other way around there are just a few computers that will allow you to do whatever you decide without penalizing you.

As far as Suunto goes, they're fine computers as long as you don't do much bounce dives and do depth changes during a dive. It penalized me on a vacation because of too much depth changes (photography, less than 20m). In normal diving you're not very likely to experience any issues but it can limit you for sometimes not so obvious reasons. Enough reason for me to ditch it and go fo a Shearwater. A Shearwater will allways give you it's opnion without judging.

 

[scubadada]

My opinion regarding Suunto RGBM has evolved somewhat over the years. I dive computers running DSAT and Buhlmann ZH-L16C with gradient factors and am used to relatively liberal NDLs.

I think the basic Suunto RGBM algorithm is more middle of the road rather than on the very conservative end of the spectrum. You can see this if you look at the multiple dive testing done by ScubaLab. Suunto was last tested in 2016, you can find it under Scuba Diving Magazine computer tests. There is very little controlled multiple dive testing data available. The results are perhaps explained by the dive conditions. The hyperbaric chamber dives are tightly controlled with a normal ascent between depths and a one hour SI between dives 1&2 and 3&4 and a two hour SI between dives 2&3.

On a liveaboard, SIs are generally an hour or longer, even with 4 or 5 dives per day. The effect of short SIs is less likely to be observed. I do much of my diving in SE FL where the SIs between 2 morning or afternoon dives is often considerably shorter than an hour. It is under these conditions where I have accumulated my anecdotal experience that Suunto RGBM is more conservative. So...I think the results are influenced by the specific dive conditions, as nicely pointed out by @Lorenzoid and others.

 

[tursiops]

Best to dive with the same algorithm (Suunto is fine) that your dive buddies use. Otherwise, somebody is going to be unhappy.
In the US, I see few Suuntos; elsewhere, many. It is very much a marketing and distribution thing, not a an algorithm thing.

Beware, however, the VERY different approach to customer support: Shearwater is probably one of the best, Suunto, not so much.