Oceanic vs Mares vs Suunto Algorithm

[scubadada]

Reboarding without a deco obligation should be sufficient. Personally, I've never had anyone check my computer profile, that really should be the diver's responsibility.

Good diving, Craig

 

[DiveNav]

There is something wrong with that chart, the teset was done wrong or one of the computer was bad. The wisdom 2 use the DSAT algorthim but it does'nt track with the OC1 and they are made at the same factory..

Maybe the Wisdom 2 conservatism setting was different?

 

[tstormdiver]

What seems strange to me is, it seems easier to use a liberal computer and dive more conservatively if you wish (say, colder water with poorer viz. & some strenuous exertion due to current), vs. to dive a conservative computer & push (and risk violating) the NDL limits. Aside from the hassles this can create diving with buddies with liberal computers who don't want to cut their dive time short, if you dive a live-aboard and violate your computer's NDL & enter deco., it's my understanding from some prior post on the forum that the crew might basically 'bench' you for the remainder of the day.

That said, I've wondered why some people choose Suunto computers (I've never used one, have no other beef with them & obviously they are quite popular). Is there any inherent advantage or selling point to a Suunto compared to an Oceanic or Aeris? Is the interface easier to work, the display sharper, the battery longer lasting, the hardware more reliable, the bundled software for PC download better implemented, etc???

I'm not anti-Sunto, I just wonder what makes people pick them (IF their good qualities are matched by competitors). I don't usually see Sunto users claim to chose Sunto because of the conservative algorithm.

Richard.

2 Reasons, I have bought Suunto's. 1. until recently, they have been rock solid in quality. Where my LDS would have to send back in Oceanic or UWatech computers for various problems, Suunto's rarely had to go back for anything. Now, Suunto's quality has dropped some & problems are beginning to appear. 2. My first Suunto was a HelO2. I wanted a decent, but affordable trimix computer for future use. The HelO2 fit the bill. Now it seams that Oceanic has picked up the ball & has improved quality.

I wasn't crazy about the conservatism of the Suunto's, but they were a bit more liberal & more affordable, than the Dive Rite HE's, when I was looking for a computer of that type. Now the Shearwater Predators are stepping up to the plate for affordability, reliability & the ability to make them as aggressive or conservative as you want.

 

[ElChe]

"Is there any inherent advantage or selling point to a Suunto compared to an Oceanic or Aeris?"

My reason is quality. I had an Oceanic which died after 1,5 years, a friend had the same problem with Oceanic too and I heard about several other divers who had quality issues as well. The Suuntos and Uwatecs are usually works for 10+ years, although the newer models seem a bit less sturdy. I found the Suunto a bit more user friendly than the old Uwatec models, but basically both of them did the job. Certainly if somebody can afford new computer in every second year (because he or she needs gas change, trimix features etc) it's not a problem but from my point of view an ordinary diver will be happy with an entry level Suunto or Uwatec for decades. If somebody is luckier than me and use Oceanic for years without any problems I understand if he loves that computer, because it's nice too. But I don't give them another chance...
About conservative algorithms: I'm a conservative diver, never wanted to brake any rules so for me the Oceanic as safe as anything else because I don't dive on the limits. I saw a buddy who didn't get into deco (Suunto) but later had to go to the deco chamber- my choice is to be conservative...

 

[redacted]

Unfortunately some divemasters take that view as driich2 points out that if your computer goes into any deco you're reprimanded. It's a mindless approach that follows a rulebook rather than logic. If you do the same dive and for one computer it's a no deco dive and another has a short deco stop, it's the same dive, but the diver following the latter does a safer, slower ascent. The maxim "every dive is a deco dive" applies to this.

Mindless is opting for a known conservative computer and then diving it to is limits and beyond. While all dives involve off-gassing (some call that deco) only those dives that go beyond recreational limits involve ceilings that your computer says you must honor. I don't understand why you would think it is smarter (or safer) to opt for a conservative computer and then push it beyond the conservative limits you chose. I'm sure, if you do the occasional deco obligations required, you will be reasonably safe and effective. I am not sure that is still true if you routinely plan and conduct deco dives with it. Remember, the RGBM model may invoke longer SS and SI as you push the limits of its NDLs so you may be getting ever more shortened subsequent dive times as you extend your earlier dives with "light deco". Plus you risk the problem of your possibly unnecessary deco obligation on a recreational dive conflicting with the rest of the group's dive plan or even an emergency diver recall. And you don't understand why your DMs do not approve?

If you insist on diving more aggressively than your conservative computer recommends, maybe you need a more liberal computer. Maybe you should look at the computer of the guy you say you are diving the same as who does not incur a deco obligation.

Let me guess - The DMs who objected to your practice of planned "light deco" were waiting for you as you were the last diver to re-board the boat. How long did you keep the rest of the boat waiting for you to complete your deco obligation?

 

[NCadiver]

Maybe the Wisdom 2 conservatism setting was different?

Maybe on dive two but the rest of them are to far off to be in conservative mode.

 

[Bubbletrubble]

Mindless is opting for a known conservative computer and then diving it to is limits and beyond. While all dives involve off-gassing (some call that deco) only those dives that go beyond recreational limits involve ceilings that your computer says you must honor. I don't understand why you would think it is smarter (or safer) to opt for a conservative computer and then push it beyond the conservative limits you chose. I'm sure, if you do the occasional deco obligations required, you will be reasonably safe and effective. I am not sure that is still true if you routinely plan and conduct deco dives with it. Remember, the RGBM model may invoke longer SS and SI as you push the limits of its NDLs so you may be getting ever more shortened subsequent dive times as you extend your earlier dives with "light deco". Plus you risk the problem of your possibly unnecessary deco obligation on a recreational dive conflicting with the rest of the group's dive plan or even an emergency diver recall. And you don't understand why your DMs do not approve?

If you insist on diving more aggressively than your conservative computer recommends, maybe you need a more liberal computer. Maybe you should look at the computer of the guy you say you are diving the same as who does not incur a deco obligation.

With respect to OW recreational diving...
There is no bright line between "necessary" and "unnecessary" deco. The deco algorithm being used by a computer does represent one, though. There is so much variation in human physiology and DCS susceptibility (and there's so much we don't know about DCS pathogenesis) that it seems kind of silly to split hairs over a gray area dive profile that puts a diver into "light deco" on a conservative algorithm and remains within NDLs on a liberal algorithm. Because of this, I don't think it's unreasonable to view what the computer displays as simply a guideline. It should be acceptable for a diver to just carry out his dive plan and let his computer follow along.

In practice, given adequate gas supplies, I see nothing wrong with an experienced, thoughtful diver who occasionally goes into "light deco" on a Suunto computer. The diver should, however, have solid gas management skills. In the rare case of an emergency diver recall, there's a good chance that no one else will be diving anymore for that day anyway.

As for the scenario in which the DM/boat is waiting for the last diver to re-board...
I think that, out of courtesy to the other paying customers on the boat, the DM/dive op should give explicit instructions to divers about when they should be back on board. Here in SoCal, for multiple boat dives at a given location, dive ops will give "gate times" specifying when divers can enter the water and will also inform the divers that, at the latest, they should re-board the boat 1 hour after gate closure time. DMs who instruct divers to "dive your computer" and/or "avoid going into deco" aren't accounting for the differences among computer algorithms. As such, they shouldn't be sweating a diver who ends his dive a little later than the rest of the people on the boat. It's easy to come up with scenarios in which either conservative or liberal deco algorithms can cause divers to re-board "late."

 

[audiotyro]

@Bubbletrubble - You're right about buddy teams not separating till exit. We also follow this rule majority of the time. There are isolated cases when my wife begins to feel uncomfortably cold and requests that she go to the surface since her computer gives her the all clear. I'd probably have a minute or 2 in mine. If we do split up she usually ascends with another buddy group and I stay with the "in-water" DM. I guess this is why I would want our computers to be on the same algorithms so time intervals will be tight if the need arises for someone to ascend earlier. Specially since it would now involve our son.

@everyone Great discussion on algorithms. Learning a lot from you guys.

 

[Bubbletrubble]

@Bubbletrubble - You're right about buddy teams not separating till exit. We also follow this rule majority of the time. There are isolated cases when my wife begins to feel uncomfortably cold and requests that she go to the surface since her computer gives her the all clear. I'd probably have a minute or 2 in mine. If we do split up she usually ascends with another buddy group and I stay with the "in-water" DM. I guess this is why I would want our computers to be on the same algorithms so time intervals will be tight if the need arises for someone to ascend earlier. Specially since it would now involve our son.

@audiotyro: Buy your wife a hood, hooded vest, or thicker wetsuit. She'll stay warmer during the dive and actually enjoy being underwater. Alternatively, you can just shorten the dive so that everyone in your buddy team can stick together.

Resolve to end all of your dives together as a buddy team. I can't emphasize this enough. In order to manage a 3-person dive team properly, you need to be disciplined, particularly in this respect. Many dive accidents/issues occur during the ascent and descent phases of the dive. There's also the possibility of a diver experiencing an emergency at the surface.

For your purposes, I still maintain that it really isn't necessary to purchase 3 computers with the same deco algorithm.
Communication and a little experience make different computers in a buddy team a non-issue.

FWIW, what a diver's computer says shouldn't be the sole determining factor on whether/when he ascends. I use a Suunto (conservative), and I've done hundreds of dives with a buddy who uses a Sherwood Wisdom (liberal). Without exception, we have always ascended together. It's a philosophy thing, not a computer thing.