Are Suunto Zoops super conservative?

[Alex Locke]

Hi,

Just recently did a reasonably deep 2 tank dive. Kept a virtually identical dive profile as the others I was diving with - neither of them went into deco but somehow my Zoop put me into around 25 mins of deco. I decided to ignore it as my profile was identical to my buddies, and to go by their watch.

I have since set my zoop to 32% O2 - is there any other way to make it less conservative? Seems a bit ridiculous that it puts me into deco when others have around 15+ mins of deco time left.

Apologies if this is wrong place to post.

Thanks

 

[RayfromTX]

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[yle]

Suuntos are known to be on the conservative side. I've been using a D4 for years (I believe it uses the same algorithm as the Zoop) and have found the same thing that you experienced. Sometimes the dive boats would make a little joke about it, during our surface intervals comparing NDLs for our next dives. Suuntos would always give the less time than just about every other computer. You will likely get some responses here that give you more detail about the algorithms used by different computers, but what it comes down to is... yes, Suuntos are conservative.

With that said, I've always followed my Suunto, planned my dives accordingly, never felt that I was unfairly limited... and I'm closing in on 1000 dives in 8 years with zero incidence of DCS. So there's that.

There is a conservatism option in the Zoop. It's possible it was set to a more conservative setting than the default setting. If you're still using it, you can look up the menus (available online) and check that. If you need help finding it, just ask (I have a Zoop also.)

As for setting your computer to 32% so it will give you more time... keep in mind that the computer just provides information to allow you to make informed decisions. It's kind of like the dashboard of your car. If the engine light on your car lights up, you can cover it with tape and ignore it. You can also claim "well, my friend's engine light isn't on... so there's no reason mine should be on either!" You can explain that logic to the tow truck driver.

Just keep in mind there are pros and cons to both conservative and not-so-conservative diving.

 

[Steve_C]

Where you and the other divers diving the same mix? If you had air and they were diving Nitrox that can make a big difference. You should not set your computer for 32% if you do not have 32%, I would not ignore my computer and just follow others. They may actually have a different mix and average a bit higher than you.

Having said that I dive with two computers. A zoop and a scubapro sport. Most of my ocean dives are from a boat in 60-95 ft of water. My mixes are usually 32 sometimes 30. On dive one the two read almost the same. On dive 2 with a one hour SI the sport will give me about 15 minutes of NDL more than the zoop this is consistently. Also if I go up a bit the sport usually gives credit quicker.

 

[BoltSnap]

There is no polite or "flame free" word or expression that I can use to describe what you are doing with the computer.

I have been diving for over 40 years and an instructor for over 30 years now and I have been using Suunto computers (many models) since circa 1994 and I have NEVER thought to do what you are doing at all. What you are doing by either ignoring the deco time the Zoop is giving you or "going by your friends watches" or actually setting the O2% to 32 when you aren't using 32% O2 is beyond words, any words not just cuss words. 32% not 22 or 28, 32%!!!

If you are unhappy with your computer, sell it and get one that your friends or dive buddies use and follow YOUR OWN computer and never fiddle with the O2% unless you are using gas that has this O2% you are ACTUALLY using. I am not sure if you realize it, when you set the O2% to 32, you aren't only messing up your deco status U/W for this particular dive, but you are making a total mess of your repetitive dives, TOTAL mess.

There is no way to do what you want your Zoop to do other than selling it and getting another computer of the type you like. What is better is for your is to seek a knowledgeable instructor or a highly experienced diver who understand dive computers and deco algorithms and have them explain to you how to use a dive computer and especially safety rules with dive computers. If you don't, I don't know of any different method of telling you this, you are going to get yourself very badly hurt if not killing yourself.

 

[boulderjohn]

As Burhan said, either use a computer as it is designed or get a different computer. If you are going to invalidate it the way you are planning, you might as well throw it away and just do whatever you feel like.

If you are ridiculously off from the rest of your friends, the odds are there is something wrong with your settings. Take some time and go through the manual carefully to make sure everything is correct.

 

[yle]

There is no polite or "flame free" word or expression that I can use to describe what you are doing with the computer.

Burhan, I agree with everything you've written, and it seems the OP could use a refresher on the use of dive computers. But there's a real learning opportunity here (considering the forum this thread is in), and it involves a weakness of modern OW courses that teach divers to follow their computers.

Too many OW divers are taught math is hard, let your computer do the math, then just do what your computer tells you. The message this sends is that the computer is giving the diver permission to dive, and that the diver must obey the computer.

But then a diver discovers a loophole! They can fiddle with the settings and the computer will grant them more time, give them "permission" to dive for more time.

The solution to this problem is to stress to new divers that the computer does not give permission, it only provides information based on its calculations. The diver is responsible for making all decisions, and should make informed decisions to dive as safely as possible. I don't feel this idea is hammered into enough new divers. Which is why they convince themselves that if they obey a computer (regardless of how they fiddled with the settings) everything will be fine.

If new divers are beat over the head (figuratively) with:

1. YOU are responsible for planning your dive and making all decisions related to the dive

and

2. the computer simply provides information to allow you to make those decisions

I think we'd see far fewer situations like the one described by the OP.

 

[fmerkel]

Yes, they are conservative. Push them and that's the result you get. Ask the question and this is the result you get.
FWIW, my wife has been setting hers at 26% for use on 21% air for SINGLE TANK local diving to approximate my UWATEC Aladin. I asked about doing that about a year ago and the results were......interesting.

You DO mess with the basic algorithm by messing with the %.. You DON'T know exactly what you are getting. The results may be cumulative, and probably are. OTOH, the Suunto computers are a 'black box' and you don't know what is going on in there.

If we had known NOW what we've learned over the last 2 years Suunto would not be on our purchase list. They have a more issues than just being conservative.

 

[Centrals]

Buy a more liberal computer and set your Sunnto to gauge mode and use it as back up timer.
I had came across suggestion on setting the computer to AIR mode but breath with nitrox but never the other way round.

 

[BoltSnap]

Burhan, I agree with everything you've written, and it seems the OP could use a refresher on the use of dive computers. But there's a real learning opportunity here (considering the forum this thread is in), and it involves a weakness of modern OW courses that teach divers to follow their computers.

Too many OW divers are taught math is hard, let your computer do the math, then just do what your computer tells you. The message this sends is that the computer is giving the diver permission to dive, and that the diver must obey the computer.

But then a diver discovers a loophole! They can fiddle with the settings and the computer will grant them more time, give them "permission" to dive for more time.

The solution to this problem is to stress to new divers that the computer does not give permission, it only provides information based on its calculations. The diver is responsible for making all decisions, and should make informed decisions to dive as safely as possible. I don't feel this idea is hammered into enough new divers. Which is why they convince themselves that if they obey a computer (regardless of how they fiddled with the settings) everything will be fine.

If new divers are beat over the head (figuratively) with:

1. YOU are responsible for planning your dive and making all decisions related to the dive

and

2. the computer simply provides information to allow you to make those decisions

I think we'd see far fewer situations like the one described by the OP.

I believe that teaching students, especially in the entry level dive course, how to properly use dive computers is just as important as teaching them how to use dive tables and about the basics of deco. theory. Not to do so, is a disservice to these students.