Do I really need an expensive dive computer??

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Curious. How do you estimate your depth with reliability?

LOL...uh look up, yep I'm underwater. Really at rec depth, who cares. As long as I know I have air, I can figure it out. No SPG, who really knows...

Have you ever ran out of air? I have several times and was conscious that it was going to happen.

Hell no and I don't really care what it feels like and I don't recommend it to others (that's like the cardinal sin of diving...isn't it?? :)). I'm far from a chicken little, but the idea of making my tank look like a coke bottle doesn't appeal to me. To be honest admitting you have experience with it (several times) isn't something I would admit to (especially in the Basic forum, unless you're an old timer using a j-valve then maybe I would give you props). :)
LOL...did I miss something in the thread...:idk:
 
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Sorry guys...but if I have to have one or the other, I'll take an SPG every time over a depth gauge. I can estimate my depth, but running out of air will kill you. Of course I'm a warm water diver so my viz is usually pretty good. :) IMHO, YMMV.

LOL...uh look up, yep I'm underwater. Really at rec depth, who cares. As long as I know I have air, I can figure it out. No SPG, who really knows...

Hell no and I don't really care what it feels like and I don't recommend it to others. I'm far from a chicken little, but the idea of making my tank look like a coke bottle doesn't appeal to me. To be honest admitting you have experience with it (several times) isn't something I would admit to (especially in the Basic forum, unless your an old timer using a j-valve then maybe I would give you props). :)
LOL...did I miss something in the thread...:idk:

Curious as to why you suggested it is a better idea to estimate your depth rather than deal with no SPG in the basic forum then, given you are admitting you really can't. If I have to lose one, I am going up and the one most useful to me will be the depth gauge. The SPG won't matter at that point.

If you are talking about doing a dive start to finish with only one of them, estimating your depth is a fools game, especially in warm water with good vis. That bottom that looks so close when you are @ 60 FSW could be @ 200 FSW and you have no idea where in the water column you are. Yes, it can kill you just as easily as OOA, and could be the cause of OOA. Think you have enough air for an hour @ 50 FSW? Doesn't matter if you wind up @ 90 FSW and "estimate" you are @ 50 FSW. You'll be OOA before you know it.
 
Curious as to why you suggested it is a better idea to estimate your depth rather than deal with no SPG in the basic forum then, given you are admitting you really can't. If I have to lose one, I am going up and the one most useful to me will be the depth gauge. The SPG won't matter at that point.

I was probably unnecessarily flippant and wasn't taking into account different environmental situations such as low viz (I'm a tidy bowl diver myself, warm and blue), but I've been on many dives where depth isn't that much of an issue (i.e. 30 ft. reef bimbles). For that matter I can gauge my depth pretty well in the conditions I dive in by looking up, at my surroundings, and feeling the difference in pressure at various depths (certainly not within a couple feet, but enough to stay out of trouble on most recreational dives). Also, my buddy can tell me my depth, but he can't tell me how much gas is in my tank.:) If for some reason my depth gauge malfunctioned, I might go ahead and continue my dive for a bit depending on the circumstances. On the other hand, if my SPG failed my dive would be over as the loss of that information could be immediately catastrophic. While depth is certainly a big factor in gas usage, it doesn't make it magically disappear. If you have an SPG you at least know what you have and can make decisions based on that information.

Also, equating me being a bit flippant about calculating my depth vs. somebody talking about running out of air on multiple occasions is being a bit disingenuous (especially in the Basic forum). IMHO. :)
 
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I was probably unnecessarily flippant and wasn't taking into account different environmental situations such as low viz (I'm a tidy bowl diver myself, warm and blue), but I've been on many dives where depth isn't that much of an issue (i.e. 30 ft. reef bimble). For that matter I can gauge my depth pretty well in the conditions I dive in by looking up, at my surroundings, and feeling the difference in pressure at various depths (certainly not within a couple feet, but enough to stay out of trouble on most recreational dives). If for some reason my depth gauge malfunctioned, I might go ahead and continue my dive for a bit depending on the circumstances. On the other hand, if my SPG failed my dive would be over as the loss of that information could be immediately catastrophic. Also, equating me being a bit flippant about calculating my depth vs. somebody talking about running out of air on multiple occasions is being a bit disingenuous (especially in the Basic forum). IMHO. :)
Imho as soon as your depth gauge or dog fail your dive is over you can't tell how deep you are I know where I dive in the same areas the depths fluctuate all the time.
No depth gauge no spg no dive
 
Imho as soon as your depth gauge or dog fail your dive is over you can't tell how deep you are I know where I dive in the same areas the depths fluctuate all the time.
No depth gauge no spg no dive

I certainly agree. I wouldn't undertake a dive without both. Given the hypothetical of losing one or the other during the dive, I would be more concerned about losing my SPG. I was just saying I've been on many dives where depth wasn't nearly as critical. I'm not recommending you should dive without either one, but I'm definitely recommending you NEVER go OOA. IMHO, YMMV :)
 
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I certainly agree. I wouldn't undertake a dive without both. Given the hypothetical of losing one or the other during the dive, I would be more concerned about losing my SPG. I was just saying I've been on many dives where depth wasn't nearly as critical. I'm not recommending you should dive without either one, but I'm definitely recommending you NEVER go OOA. :)

I think we can all agree on that!
 
Imho as soon as your depth gauge or dog fail your dive is over you can't tell how deep you are I know where I dive in the same areas the depths fluctuate all the time.
No depth gauge no spg no dive

I think that's a bit too broad a statement, at least if I can figure out what you mean by "dog" failing. As often as I've been tempted, I've never taken my dog diving. :)

I'm perfectly comfortable finishing an open water dive with no SPG or depth gauge as long as I'm with a trusted buddy. I can stay at his depth and share air if needed. I dive in a way that I more-or-less know my air consumption based on dive time and depth, and as long as I dive the plan I made, I'm not that worried about running out of air, in OW recreational settings. Overhead or technical diving, very different story.
 
LOL, you don’t know me very well.... my entire dinner/bar tab for a week in Grand Cayman was under $200. I Know about pricing paying wages, etc.... and $3-400 for the computer is fine. The cost of $90 for a piece of wire with connectors on the end seems very steep when compared to the sophistication and complexity of the computer itself.
Under $200? Where you hunting chickens?
 
The convenience of having your tank pressure numbers right there on your wrist is tough to beat as well as having the computer calculate your most limiting factor (N02 or gas remaining) and giving you a digital readout of dive time remaining. No reaching for a large gauge cluster and bringing it in front of your face and you don't have the extra bulk on the end of the hose. What I do is backup my AI wrist computer with a mini SPG on a thin hose, which is tucked behind my BCD with the gauge clipped off to a lower D ring. Hardly know it's there, and it's handy when I first check my rig on the boat- with the AI computer you gotta hold your wrist close enough and wait for the signal, with the SPG it's instant. And in the rare event I would have a failure of my AI wrist unit, I don't need to call the dive. I never paid more than $250 for the wrist unit and transmitter, always buying a used, older model that has all the important features except maybe multiple gases at once and "buddy check", or colorful screens and menus.

This, precisely. I got an Aeris Elite T3, with a transmitter, for 226€. It had 110 dives on it when I got it, so it should have plenty of life left in it. It's super handy - I can see my remaining air without taking the hands off my camera rig, it estimates my remaining dive time for both NDL and air, showing me which one is the limiting factor and by how much, same for oxygen loading if I'm diving nitrox, and probably best of all - the air consumption estimate is dynamic, so if I start breathing hard, I can immediately see my remaining dive time estimate plummet - and then recover once I get the breathing under control. It's got a couple quirks - the backlight is so weak that it's totally useless, and it goes into a safety stop mode considerably earlier than it's set for - when I had it set for 5 meters, it'd start the countdown at something like 8, and now that I have it set for 4 meters, it starts the safety stop at 5.4 - but it's nothing I can't live with. As a backup, I have a little SPG on a hose clamp clipped to the lower left side of my BCD.
 
My criteria for a computer is not based on cost. It is based on whether i can use it or not. too many buttons means to many things to remember. hold buton A for 5 seconds and then button C for 2 seconds while pushing button B accesses the the set up screen. If yo have to do that crap then you dont have a computer. If I have to have a book to figure how to change the nitrox mixture then it is not the computer for me. Much like obama care if you policy wants you to may 8k for the policy and then have a 10k deductable and a 2k copay ,,, then you really dont have insurance.
Back to computers..... I use a shearwater. 2 big (wearing gloves) buttons,,,, one scrolls through perhaps 5 different areas like set up select gas ect and the other selects what you have scrolled to. 5 minutes with the manual and you can throw the book away. At least for the non rebreather side of things. Rec or tech its the same. On behalf of other computers the default screen is probably all you need (in reality) for diving an air dive. The nitrox world has changed things cause yo have to navigate the menus to change the gas mix you are using which again should not need a book. Simple dives allow you to set up things on land. BBBUUUUTTT if you are going to do a gas change mid dive you best not need a book to do it. Next is ability to read the computer with less than perfect vision. 1001 degreees of doing that. The ability to change batteries easily is a must for me. It may not be for you if you use it a dozen times a year and a battery is good for 100 dives. One bad battery change resulting in an o-ring leak and it makes no difference if the puter is 250 or 1250 dollars. and then if the battery goes dead and you cant fine one then you have no battery/ have no computer. I personally am not confident that my watch type of computer could survive my changing a battery. My shearwater sure can and use any wallmart battery that you can fit in the compartment. References to blue tooth was made. I love it no 100$ dongles to both try to make work or worry about loosing. I think it is unfortunate that new divers have no clue what they are looking at when the shop is pushing their computer inventory on you. after many many years of diving with computers my shearwater cost me probably 5000 $ 500 for the shearater and the rest for so many other computers that with out a book i cant nav the menues to do routine functions.

So perhaps it is fare to say the the show case price means nothing if you cant use it.
 
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https://www.shearwater.com/products/perdix-ai/

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