100' vs 130'??

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My Perdix does not have mandatory deco stop if I dive deeper than 40m. Only if I exceed NDL.
It does have MOD 57m on air though at PPO2 1.4
View attachment 670164

MOD - Maximum Operating Depth of a gas is simply the dose (as PPO2) divided by mix.
Thus "What is the MOD for 28% bottom gas" is answered using the dose as PPO2 = 1.4, so
dose / mix = MOD(ATA)
1.4 / 0.28 = 5ATA = 40m/132'

On a Suunto, they calculate it as 38.7m Some blather about "adding 2% for safety", or is it fresh v salt (it's the pressure that counts, not the measurements)
 
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Oh struth... Please don't say that you're actually recommending Suunto computers over Shearwaters. It's like little league over the New York Dandies (I don't do sport).

Suuntos: recreational toy computers with ridiculous conservative settings which lie about basic facts, are difficult to use (how many buttons with short/long combinations), lock up if you've dared to ignore it or change modes, and have proprietary decompression algorithms that keep you in the water too long. Batteries which will give up when you need them (their warning is that the battery's failed just before you dive). It won't let you change gasses until you're above the MOD (which is wrongly calculated), so have to go to 5m to switch to 100%.

Shearwaters: extremely reliable, usable and dependable dive computers used by most technical divers and the majority of rebreather manufacturers. A single AA battery available anywhere. Algorithms which are basically open-source so there's loads of planners. Extremely clear in the water and exceedingly easy user interface (vital if you're befuddled underwater). They have "tech" modes with more info and "rec" modes for simplicity. They don't lock up if something's gone wrong. They allow you to change GF-Hi if you're in the poo and need to get out quickly.

In other words, Shearwaters are designed by divers and work with you, whereas Suuntos seem to have been designed by people who don't dive and they spend their time working against you.


***
Shearwater dive computers are a bit like Apple's iPhone: when they came out in 2007 it was a breath of fresh air and a vision of the future, compared with the previous generations of phones, PDAs & Blackberries.

I'd had three different dive computers before I bought my first Perdix. Rented Suuntos early on which were only depth gauges and timers, had an XDeep Black (now there's an unreliable brick), and a Suunto D9tx ('cos I believed the hype and didn't know any different).

Needless to say the Perdix was an utter revelation; reliable, easy to use and just worked. Just like my iPhones.

Wow! I'm feeling pretty bad about now since I have a Suunto Nova. But, also, I'm a newbie and hence my original question of 100' vs 130'. I do plan to get my advanced in February and nitrox at the same time. But, I don't plan on going to beyond 60' until trained and probably rarely after that. There is still a lot above 60' that I'm interested in. So I'll continue to learn and hone my skills. When I outgrow my Suunto, I'll definitely look at Shearwater, although I probably have a few more years with my Suunto.
 
Wow! I'm feeling pretty bad about now since I have a Suunto Nova. But, also, I'm a newbie and hence my original question of 100' vs 130'. I do plan to get my advanced in February and nitrox at the same time. But, I don't plan on going to beyond 60' until trained and probably rarely after that. There is still a lot above 60' that I'm interested in. So I'll continue to learn and hone my skills. When I outgrow my Suunto, I'll definitely look at Shearwater, although I probably have a few more years with my Suunto.
The Suunto will be absolutely fine for your diving.

It’s limitations come to play when doing deeper and longer dives outside of recreational diving limits. My beef is they make a big thing about their kit being ‘technical' when it isn’t — damn marketeers lying and exaggerating as ever.
 
Wow! I'm feeling pretty bad about now since I have a Suunto Nova. But, also, I'm a newbie and hence my original question of 100' vs 130'. I do plan to get my advanced in February and nitrox at the same time. But, I don't plan on going to beyond 60' until trained and probably rarely after that. There is still a lot above 60' that I'm interested in. So I'll continue to learn and hone my skills. When I outgrow my Suunto, I'll definitely look at Shearwater, although I probably have a few more years with my Suunto.

I have Vyper Air myself (that is still working) and it is fine as long as you don't violate its alarms otherwise it will make you sit in a corner and lock you out of diving for a very long time :)
 
.Oh struth... Please don't say that you're actually recommending Suunto computers over Shearwaters. It's like little league over the New York Dandies (I don't do sport).

Suuntos: recreational toy computers with ridiculous conservative settings which lie about basic facts, are difficult to use (how many buttons with short/long combinations), lock up if you've dared to ignore it or change modes, and have proprietary decompression algorithms that keep you in the water too long.

Needless to say the Perdix was an utter revelation; reliable, easy to use and just worked. Just like my iPhones.

My Suunto Vyper had the normal pressure sensor failure and Suunto refused to repair it as it was out of warranty. I had seen the Petrel but as the Perdix was out I decided to get that. As you wrote the Perdix was an utter revelation; reliable, easy to use and just worked.

Best thing was how easy the screen was to see in any conditions. The Suunto had a backlight for low vis ( useless ) and for night dives when meant having to press a button and even then the backlight was insufficient. Two large easy to use buttons on the Shearwater versus 4 small buttons on the Suunto which were difficult to use on a dive. If someone asks me about Sunnto I just reply read about their lawsuit and pressure sensor failures and bad service to customers v Shearwaters service to customers with even out of warranty devices being serviced or replaced for free. I would say look at the Shearwater Peregrine but if you can afford it just go for the Perdix or if you like a watch the Teric.

Big plus on the Perdix is the ease at which I can change the single AA battery. Cannot do that on the Suunto. Need special tools and special battery.
 
For certain operations you’ll need to show AOW to be able to dive the deeper dives.
Some liveaboard operations even require at least x (30, 50) dives below 30 meters to do rec deep dives.
 
Some liveaboard operations even require at least x (30, 50) dives below 30 meters to do rec deep dives.

Well they have the right to set policy. My average max depth over my last 250 dives is 26.5m I'm sure I have more than 50 of those dives deeper than 30 meters.
 
Some liveaboard operations even require at least x (30, 50) dives below 30 meters to do rec deep dives.
Interesting. I have never heard of that before. Can you post a link to a liveaboard with that policy?
 

Why didn't you quote the entire statement? Here it is in full:
We were most excited for healthy coral reefs, the Picasso-like mandarin fish and blue-ringed octopi – but the crowning glory of this place are the ethereal thresher sharks that grace Monad Shoal in the early mornings. Ideally, our participants needed at least 30 logged dives with deep (30 meters) and night diving experience. But for the ones who didn't, Evolution helped organize extra training for deep and night diving so that they didn't miss out!
Here is what you wrote earlier:
Some liveaboard operations even require at least x (30, 50) dives below 30 meters to do rec deep dives.​

The review you cite does not remotely refer to a requirement of "at least x (30, 50) dives below 30 meters to do rec deep dives." Not even close. It says that "ideally" divers should have "30 logged dives" (which is barely anything) and an unspecified amount of experience going to 30m, not 50 dives below 30m. That quote could be accurately rewritten as "Ideally, you should have at least 30 logged dives with some night dives and some dives to 30m, but if you don't, no worries--they'll make sure you get the training you need for that." I see that as inviting pretty much anyone with any experience to do the trip.

EDIT: After writing this, I realized your problem with it might be related to English not being your primary language. You might have understood the phrase "at least 30 logged dives with deep (30 meters) and night diving experience" as requiring 30 deep dives, but that is not what it means. It means that ideally you should have 30 total dives, and those 30 dives should include some night and deep dives.
 

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