Question about dive computers

[Neilwood]

I am actually enjoying the discussion here. Always happy to learn.
For my purchase, I am actually looking into computers that have been in the market for a few years. Scuba gear is pretty expensive for me locally so I was thinking of buying it from a different country. But if it fails, I won't be able to claim warranty.

Good to hear about you being happy to learn - decompression algorithms are a minefield and it is worth spending some time being comfortable with what you end up going for.

There is are a couple of statements (I don't have the time to find the actual quotes so I will paraphrase them but this will give the gist of what they think) that bear thinking about in this (both came from specialists in decompression medicine):
1) All models are wrong but some are useful.
2) Ask a new diver about what causes decompression sickness and they will tell you they aren't really sure, ask an experienced diver or instructor and they might tell you its all about micro-bubbles ascent rates etc but ask a decompression scientist and they will tell you they aren't really sure.

Knowing whether your algorithm is considered conservative or aggressive or the little things (such as sub 1hr surface intervals having a disproportionate effect) can affect how you dive. It is also worth noting that all algorithms are statistical in nature and that even following your computer perfectly does not guarantee you 100% safety from DCS.

Another thing that hasn't really been touched on by a lot of the posters above is that you might want to consider your algorithm (and conservatism) with regards to your age, general health, hydration etc. I would be more willing to dive an aggressive DC if I were 20 years younger and fit but as a mid 40's diver with a bit more padding than I should have, I will dive a bit more conservatively.

 

[kelemvor]

Everyone makes this seem so complicated. I think any modern dive computer will do the job unless you get into tech diving. At that point, you're probably going to buy something new anyway.

So, look for the features you like. Do you want air integration? Do you want to download logs to a pc or cell phone? Do you want a bright display or an lcd? All of those are optional. Generally, they cost money to have. None of them are necessary.

Personally, I like them all - and I'm willing/able to pay for them. Not everyone agrees, or there would be far fewer dive computer manufacturers out there.

First computer? If you're on a budget, get a mares puck. I think they're around $250. If not, the world is your oyster. Shearwater is current top dog in the view of most divers.

 

[scubadada]

Good to hear about you being happy to learn - decompression algorithms are a minefield and it is worth spending some time being comfortable with what you end up going for...

...I would be more willing to dive an aggressive DC if I were 20 years younger and fit but as a mid 40's diver with a bit more padding than I should have, I will dive a bit more conservatively.

Despite all the brands and models, there are a limited number of decompression algorithms to choose from, see post #11
Atomic RGBM
Buhlmann ZH-L8 or 16 ADT
Buhlmann ZH-L16B or C with preset and/or custom gradient factors
Cressi RGBM
Deepblu Buhlmann variant
DSAT
Mares RGBM
PZ+
Suunto RGBM (or Technical, or Fused RGBM)

I was in my mid 40s once, I'm older and much more experienced now, I dive within my experience

 

[Jay]

I think it's mostly spotlight effect: there's a couple of regular suunto bashers and perhaps half a dozen drive-by ones, and for every one of them I've seen a dozen actual divers wearing zoops on boats. And so far nobody had a screaming fit when someone needed to stay at safety stop for an extra minute. But then again, I haven't dived in FL or MX yet, we mostly hang out with all them Dutch people...

Feel free to pull out some quotes from the "suunto bashers" but I don't think I've seen that happen on SB. What I have seen is various divers saying why they prefer (or not) various computers/algos. Happy for you to prove me wrong.

I'm not a fan of RGBM algos, mainly due to their reduced NDLs on repetitive dives, but that doesn't mean I only dislike Suuntos. You can add Cressi and Mares into that too, or any 'conservative' computer from @scubadada's post #11. But that's just me, my preference. I also don't need to have a "screaming fit" for extra stop times or reduced NDLs either. Depending on how we're diving we'll have that sorted out beforehand, and if we're in one dive group lead by a DM then it's just going with the flow. It's what I signed up for. And yes, some of my quasi-regular dive buddies/friends do have Suuntos (no Eon or Cores) and we enjoy our dives with no screaming! In that case I don't care if NDLs are shorter relative my my computer as diving with me friend is more important. And in a new group, a new insta-buddy, or even with a new heavy breather, leeway's an important attitude.

SB regulars would have seen us dance similar dances previously. What the pertinent question seems to often become is how to properly assess the relative conservatism of various computers/algos for a Rec diver. So I've made a new OP for that here:How to properly assess the relative conservatism of various algos/computers for Rec divers?

 

[Neilwood]

Feel free to pull out some quotes from the "suunto bashers" but I don't think I've seen that happen on SB. What I have seen is various divers saying why they prefer (or not) various computers/algos. Happy for you to prove me wrong.

I'm not a fan of RGBM algos, mainly due to their reduced NDLs on repetitive dives, but that doesn't mean I only dislike Suuntos. You can add Cressi and Mares into that too, or any 'conservative' computer from @scubadada's post #11. But that's just me, my preference. I also don't need to have a "screaming fit" for extra stop times or reduced NDLs either. Depending on how we're diving we'll have that sorted out beforehand, and if we're in one dive group lead by a DM then it's just going with the flow. It's what I signed up for. And yes, some of my quasi-regular dive buddies/friends do have Suuntos (no Eon or Cores) and we enjoy our dives with no screaming! In that case I don't care if NDLs are shorter relative my my computer as diving with me friend is more important. And in a new group, a new insta-buddy, or even with a new heavy breather, leeway's an important attitude.

SB regulars would have seen us dance similar dances previously. What the pertinent question seems to often become is how to properly assess the relative conservatism of various computers/algos for a Rec diver. So I've made a new OP for that here:How to properly assess the relative conservatism of various algos/computers for Rec divers?

I think for most recreational divers (unless you are doing a lot of repetitive diving ie 5/6 days of 3-4 dives per day) the NDL differences will be relatively minor between most of the DC. As you say, I would rather enjoy my dive than obsess over my dive being cut 2/3 minutes short because of his computer giving a shorter NDL. That is assuming we can both hit the point of being NDL limited as opposed to gas limited.

 

[dmaziuk]

I think for most recreational divers (unless you are doing a lot of repetitive diving ie 5/6 days of 3-4 dives per day) the NDL differences will be relatively minor between most of the DC. As you say, I would rather enjoy my dive than obsess over my dive being cut 2/3 minutes short because of his computer giving a shorter NDL. That is assuming we can both hit the point of being NDL limited as opposed to gas limited.

The differences grow non-linearly, and if you're riding your computer up to NDL 4 tanks/day for 6 days straight, better understand what it is you are actually doing. That's the part largely missing from all the "liberal" advocacy here: the clue.

 

[Neilwood]

The differences grow non-linearly, and if you're riding your computer up to NDL 4 tanks/day for 6 days straight, better understand what it is you are actually doing. That's the part largely missing from all the "liberal" advocacy here: the clue.

Agreed hence the comment (which I probably should have bolded for emphasis)

I think for most recreational divers (unless you are doing a lot of repetitive diving ie 5/6 days of 3-4 dives per day) the NDL differences will be relatively minor between most of the DC. As you say, I would rather enjoy my dive than obsess over my dive being cut 2/3 minutes short because of his computer giving a shorter NDL. That is assuming we can both hit the point of being NDL limited as opposed to gas limited.

 

[60plus]

2) Ask a new diver about what causes decompression sickness and they will tell you they aren't really sure, ask an experienced diver or instructor and they might tell you its all about micro-bubbles ascent rates etc but ask a decompression scientist and they will tell you they aren't really sure.

I am a newish diver and I thought / still think DCS is caused by nitrogen coming out of "solution" in the blood stream and organs.

Regarding my zoop novo. It has 3 different levels of "conservatism" / safety margin. I have it set on No 3, the highest because I am over weight and over 40 years old

 

[Neilwood]

I am a newish diver and I thought / still think DCS is caused by nitrogen coming out of "solution" in the blood stream and organs.

Regarding my zoop novo. It has 3 different levels of "conservatism" / safety margin. I have it set on No 3, the highest because I am over weight and over 40 years old

Nitrogen coming out of solution is the basic premise for it but what exactly is happening is not totally understood.

When you watch a video like this one you understand, despite all the studies and experts, quite how little is actually known about the subject :
Until you get DCS symptoms, you don't know how close or far you are from getting the symptoms.

There is an adage which applies to dive computers (which adequately describes the issue) - measure with a micrometer, mark with chalk and cut with an axe. The dive computer comes up with a VERY exact profile despite not knowing what you actually did on the dive, how fit you are, how well hydrated or fed you are. It could be 100% accurate for you or it might be a mile off - unless you happen to have scientists on hand who can analyse bubble formation etc you will never know.

 

[purbeast]

I figured I'd just ask in this thread instead of starting a new thread.

I am curious if anyone has used the Mares Puck Pro and the Suunto Zoop Novo. Those are the 2 that as of now I'm debating picking up before my OW checkout dives. I wanted to dive with a watch just to get used to it and see how they work and so they log my dives.

The price difference is pretty significant between the two and there is even 1 color of the Puck Pro on Amazon that is $170. I have noticed that it has less buttons (which some argue isn't a big deal) but other than that, they seem very comparable.

I'm waiting to see if Leisure Pro has any black friday sales on either of these before I make a purchase. Are there any other online SCUBA shops that I should look at as well that could have black friday deals?