My dive computer is too conservative, what can I do ?

[divin'dog]

I've just bought a Suunto Zoop Novo, but I realise that the algorithm used is on average significantly more conservative than that of the dive computers of the people I dive with (for example Aqualung).

I had one of the first dive computers from Suunto (1990) and it was based upon Navy tables... 60' for 60 mins. And it was fine. Then as more computers came out, they became more conservative, probably because the legal dept didn't want the headaches of diver lawsuits, etc. The need to be completely safe for EVERYONE.

I bought a beautiful wireless Suunto later on... But it was a pain in the arse.
1. I'd set it going out for a dive on a boat, then it would go to sleep or disconnect from my transmitter. It would be a rush at the last minute to reconnect, get it set. AND..
2. It was very conservative! Found myself coming up way before other divers even set for the most liberal setting. If I have to come up a couple / few minutes just before other divers, I'm fine. But this computer had me coming up, doing my safety and on the boat before other divers were coming up.

So I sold it and never looked back. Suunto uses RGBM algorithms and is more conservative. I bought a Sherwood and love it. It is more liberal and if I want, I can make it more conservative, but for my diving it is fine. Not the longest dives, nor the shortest dives and it fits with what everyone else on the boat is diving. YMMV.

Some info in the link below:

A Simple Guide To Understanding Dive Computer Algorithms

Not all dive computer algorithms are created equal. Learn the differences and make an informed decision when buying your next dive computer.

scubatechphilippines.com

 

[David Haas]

I come to this forum for entertainment so here's my funny diatribe

I'm on my 55th year diving after being an instructor (1978-1990), co-owning a dive shop (1985-1990) and traveling the world outside of my Ohio, USA midwest home.

The angst people have over conservative versus liberal computer algorithms boggles my brain

I am one of those whose eyes glaze over hearing gradient factor discussions, ugh, just kill me please! Too many are usually from people with health concerns that should have them diving more conservatively in my opinion.

A majority of these folks couldn't run or fast walk a mile even if chased by Zombies !!!! LOL....

They think having $$$ or deco knowledge makes them immune to bends......Well it won't and I've seen people be surprised when their turn comes around.....Hopefully just a skin bends incident if they're lucky......Most think they're Navy SEALS and woefully dishonest about their age and physical condition.

I used to dive the ORCA Pilot EAN computers actually made by BENEMEC in Finland. They were also sold as the Dacor EQUANOX, DIVE RITE Status and other branded names.

They'd NEVER lock you out, were very liberal but could be made more conservative, would penalize you a bit on repetitive dives if you did something stupid, etc.

The GOLD TOUCH contacts eventually wouldn't work and push buttons (now touch screens) eventually displaced touch buttons. To my knowledge BENEMEC moved on to other types of manufacturing.

For over 3 decades for me it's been SUUNTO. I like them and with a $75.00 SPG dive wrist mounted ZOOP NOVOs now. I dive 2, own 4 and regularly find NEW or with maybe a few dives on them for max of$150.00. They simply work, at least for me.

On the transmitters and such......Even though I see many folks using them these days almost EVERYONE (especially on long $$$$ trips) still runs a SPG! LOL.......

I'm 71 and fit for my age (no BP or other meds) and completed 29 dives in Raja Ampat, 28 in Maldives and 26 in Bali all within the last 6 months diving 32% NITROX and never ran out of bottom time.

In Bali three of us did an 84 minute dive for our buddy's AGE (he's 84). It was glorious and yes, we worked our way up slowly drifting along several dive sites to our exit point.

Our youngish Balinese dive guide (46 and smokes like a fiend but diving every day) dives his SUUNTO ZOOP NOVO every friggin' day for WORK......Granted maybe 35M max on multiple dives but OMG....it works for him! LOL......

In my 12 + trips to Philippines I saw dive guides with 5,000+ dives under their belt using SUUNTO ZOOP (original 3 button model) for thousands of dives before they died. In Raja Ampat the live-aboard co-host lady was still using a SUUNTO Gekko and early SUUNTO EON all with 3,000+ dives on them !!!

SUUNTO computers are inexpensive with user changeable batteries. The newest 4 button ZOOP NOVO is less conservative (at least in my experience) but sure, it's not as liberal as the latest Garmin or Shearwater.

So what......

If you think pushing your depths / bottom time / short surface interval is your way to dive, have at it.....Just know you're putting yourself at more risk.

For years I've never had less than 1-1.5 hours between dives. Diving NITROX on repetitive dives gets me plenty of bottom time in a day of multi-day dive trips anywhere in the world.

I understand underwater time is limited and precious and I used to be obsessed in my younger days when I thought I was bulletproof. Age gives you insights and calculations into the risks versus rewards.

I hope my comments are received as a voice of caution to just enjoy diving. Last I checked scuba diving ISN'T a competitive sport. I still enjoy diving as much as when I was 18 years old and hope to have a few more years in good health.

No photo or extra 2-3-10 minutes is worth risking life and limb so maybe consider that when discussing dive computer algorithms, Gradient Factors , etc.

When scuba gets too heavy I'll migrate to free diving (where you can still wear some cool gadget for time and depth) and keep paddling about in the sea

Just one old guy's opinion and hope it made you laugh!

David Haas

I

 

[Diver-Drex]

No one should be blindly following their computers but they shouldn’t be tricking their computer or ignoring it because they don’t like what it is telling them. Plan your profile and bottom time, plan your gas, and verify this with your instruments during the dive.

The sad truth is that most divers just jump in and follow the DM or their buddies. If they don’t or can’t plan their dives (lack of skill, lack of discipline, intentional disregard) then they should not be changing GFs, planning deco or incurring deco obligations on the fly. If someone isn’t following their computer, they aren’t looking at depth, time and most likely their SPG.

The OP’s question was about changing the O2 to 25% to get a little more time. I bet the Shearwater gets sets to 99/99. And then what happens when they leave a Nitrox mix on, and go into deco? TTS is calculated off having that richer gas and the diver only has air, and not enough to complete the stop. Or what if they can’t hold the stop depth? Not a big deal because all computers are conservative, right? Well how conservative on a cold dive when the diver is dehydrated? 1 minute, 2 minutes, 5 minutes?

Getting a Shearwater or similar can be a problem if the diver doesn’t have the knowledge, skill and discipline to complete the dives safely.

 

[LFMarm]

Getting a Shearwater or similar can be a problem if the diver doesn’t have the knowledge, skill and discipline to complete the dives safely.

If you cannot complete a dive safely, what computer you have it doesn’t matter much. Everybody who wants to dive safely should work on fundamental skills (trim, buoyancy, propulsion, breathing). I believe once skills are in check, understanding basics of decompression can increase diving safety to ensure you are not blindly getting close to dangerous behaviors, regardless of your computer and you are able to understand dive planning without the need to blindly follow a DM or buddy who may have no understanding of deco or worse they may have the wrong understanding. Once you have some decompression knowledge, then you may want to be more in control of the risk associated to your dive profiles and hence the choice of computer may be more relevant.

I don’t believe anybody should play with deco parameters and fancy computers until their fundamentals are there or they have some basic understanding of deco. And the vast majority of divers I know does not care about learning about decompression, which I believe is very risky if you want to start to push your profiles.