re: air intergrated dive computers

[coberry7]

Oh boy, lots has happened since I went away for the weekend.

Here's my quickie input...

I have heard alot on the cobra but has anyone...
I have heard alot on the cobra but has anyone experienced the scubapro smart com ????
I also have heard of some tech divers who use dive computer eg suunto and cut tables as well."

Whoever posted that, (sorry, I forgot who I copied that from), I own and have a lot of dives under some EXTREMELY different conditions with a SmartCom. I dove it before and after the recall. From Roatan, to Vortex, to the damn difficult Cooper River, SC.

Ever been to the Cooper River for fossils, SeaJay? It's in your neck of the woods. If not, I'll tell you all about it. It's a good experience!

OK, us Southerners love our Krispy Kreme's. They rock! I have been known to cut through 3 lanes of Atlanta traffic because I saw the 'Hot Ones' sign illuminated! Having been to Canada a few times I just didn't trust ya'lls doughnut capability. I stuck with Poutine and Smoked meat sandwiches, or 'Street Meat'. Of course, nothing beats a Low Country boil....MMMMMMM!! Better than Chili!!

I'll stay out of the computers versus analog versus tables or any combination thereof. Many different opinions and experiences on that discussion.

I will say that I dive a SmartCom and love it. I reccomended it to my mother and she dives one too now. I always carry tables and analog equipment in case they are required, then again, I also carry every little bit of backup gear I can topside. (Why not?) Had a reg fail on a trip once, therefore I'll never dive without a backup on the boat in order to save the dive. (mine failed as I was entering the water...)

The RBT feature of the SmartCom is neat. I always use my NDL display and remaining pressure, though to determine my RBT.

I dive, mostly in the Carribbean in shallow and DAMN deep water, but always clear water. (The Cooper River being the exception)

In any conditions, I've never had any need to worry about the info I was receiving from my computer.

With regards to the battery dying at depth....Better check the batteries before you dive! There is no excuse to be underwater with a battery that runs out of power. The SmartCom allows you to check the remaining power level of the battery with the touch of two fingers. I attended a presentation from the local ScubaPro rep last year that was directed at instructors and anyone in a dive shop selling his products. One of the questions posed was 'When is it time to change the battery in the SmartCom.' He said that even at 30% power, the computer has enough power for thirty or so dives. (If I remember correctly) I did 15 dives on mine and only lost 3 percent of my battery power. Food for thought.

That's my quickie reply!!

Colin

 

[jhelmuth]

SeaJay once bubbled...
Two of them.

There's two scenarios there.

And they aren't "worst case scenarios." They're common occurrences. Yes, I am serious.

Nobody's answered my question on how to prevent these problems. People discount my stories and say, "Yeah, but that's just a horror story" as if it doesn't happen all the time.

Trust me on this one... Do not believe your computer.

Think about it... The computer says that you have 10 minutes of gas left. You plan on that, and begin your ascent because you know that you've got a 3 minute "safety stop" to do. That's when you suddenly need to donate, 'cause your buddy's OOA. Weren't planning on that, were you? The computer can't make up for it, either. Do you refuse to give your buddy gas, or do the two of you suck down what was supposed to be ten minutes of gas left in. say, four minutes... Which is not enough time to ascend and do your stop! (It'd take 3 minutes just to ascend alone!)

The point is that the computer's "plan" doesn't account for what you really need. That's all there is to it. These aren't horror stories.

SeaJay...

I'm sorry to disagree (cause I really respect you and you are usually right on every time) but...

The SmartCOM does factor time required for ascent, breathing rates, temp., NDL, etc. in RBT (remaining bottom time). I can't speak for any other dive computer - but this I know to be true. If there are other issues which happen as a result of unexpected performance/circumstances/whatever after you've calculated your limit (and you are pushing the limit), then you are going to have a problem - computer or not.

 

[coberry7]

But DeeDee San is right on... And was really my point all along. What I was hearing prior to my examples was some really scary stuff going on there... Like the encouragement to listen to your computer rather than plan the dive. People were mentioning that the computer would tell you how much longer you can stay down... Depending on that is simply dangerous; the computer - which you're trusting your life to - simply can't gather all of the information necessary to keep you and your buddy safe.

I always tell my students that they must plan their dive, and then dive their plan. If the comp says you have more time, well, that's cool, BUT DIVE YOUR PLAN!! If your comp says you need to ascend in contradistion to your plan, then go with your comp. The most conservative way is the safest in these cases.

SeaJay, you are right. The comp cannot factor in every factor. It provides a best guess based on its input. I have read that until we have implanted dive comps in our bloodstream, then the comp is a GOOD guess as to what is going on. Tables are even worse guesses. (How many divers have you seen diving tables that do not look at their watches and write on their slates the time they surface while they wait to hand their fins to the divemaster and ditch their gear?)

I've sent shrimp out before... They get packed in dry ice. It works well.

Yup, sure does. I've even mailed fresh Bass caught from my honey hole in Louisiana to Atlanta that flew on the same plane with me in regular ice. There was one time where it was lost....I got a call from the airline a month later that they had my bag. Seems it ended up in San Diego in summer. Hate to be the guy that found that bag!!

Instead, I suggest that computers be used as they were designed to be used: as a tool. They do not replace your responsibility to plan the dive and dive the plan. Frankly, I would love to see y'all around... And if you let the computer do the work for you, that might not happen. Get my drift?

I just read this! I agree.

Also for the record: I have used my computer in "computer" mode. I don't any more... When I found myself disagreeing with the computer, I listened to the computer. That was a big mistake. I no longer wish to be tempted to listen to the computer rather than my plan and my gray matter. So... I dive with it in gauge mode. I still like the fact that it's a quality unit that shows me tons of great information... And it logs my dives for me.

What information do you plan your dives with?

BTW, the SmartCom allows you to plan your dives and it factors in your last performances. It is a lot more accurate than doing the same with tables. (Remember what I said about divers not logging their surfacing time until they are done boarding the boat, ditching their gear, blowing their snot, getting a drink, waiting for their buddy, etc.)

I cannot comment on the Vyper or any Suunto products, as I only use the SmartCom.

Colin

 

[coberry7]

And one more post.

I feel pretty strongly about this issue. This is designed for the original intent of this thread...

I do not like AI computers that incorporate radio transmitters. It is one more point of failure. I have seen at least once, which is enough, a customer that was not able to attach his transmitter to his 1st stage in such a way where it would continuosly transmit underwater the tank data.

Unless I get my HP line cut by something sharp, I will never have this problem with my SmartCom. I get the same features in my display as the AirZ Nitrox or other radio comps from Uwatec, and actually many more.

A hose is 'much gooder' than no info at depth!

For those who would like to forego a hose in an effort to streamline, then an air integrated computer is not for you, IMHO, unless you are willing to deal with the possibility of loss of transmission AT ANY TIME. BTW, you'll need a hose anyway to determine your tank pressure if you dive W/O a comp.

Colin

 

[Warren_L]

coberry7 once bubbled...
For those who would like to forego a hose in an effort to streamline, then an air integrated computer is not for you, IMHO, unless you are willing to deal with the possibility of loss of transmission AT ANY TIME. BTW, you'll need a hose anyway to determine your tank pressure if you dive W/O a comp.

Colin

I dive with a wireless AI (Vytec) and have never had any problems with the transmission. It's not that I don't think it can't happen as I would be foolish to think so, since there have been others that have complained about it. For me, it might never happen, but then again, it might. I don't use it to get rid of my HP hose. I still run a trusty analog SPG on it, which is generally permanently tucked away in a pocket or under my strap. The Vytec provides me with an easy convenient way to read my tank pressure, which has so far yet to fail me. But should it fail, I know that I can find my pressure info elsewhere.

Your one more point of failure concern can also apply to hose mounted AI computers as well. A manual SPG has no battery to fail.

 

[Groundhog246]

SeaJay once bubbled...
Think about it... The computer says that you have 10 minutes of gas left. You plan on that, and begin your ascent because you know that you've got a 3 minute "safety stop" to do. That's when you suddenly need to donate, 'cause your buddy's OOA. Weren't planning on that, were you? The computer can't make up for it, either. Do you refuse to give your buddy gas, or do the two of you suck down what was supposed to be ten minutes of gas left in. say, four minutes... Which is not enough time to ascend and do your stop! (It'd take 3 minutes just to ascend alone!)

Your examples make me wonder about your training and diving habits (no flame intended, I don't know you, only going by what I read). And someone else said "turn at 1500"!!! So 1500 out and 1500 back and on the surface with 0?
I don't dive an air integrated, I do dive a computer (cost as much as anything). I DO watch my air. For most dives it's 1/3 out, 1/3 back, 1/3 in reserve. When I reach 2000 (if diving a 3000PSI cylinder, I've some old steels too), I indicate 2K to my buddy and check his/her air remaining (after all, that's MY backup, I will also have tried breathing off my buddy's octo during gear up/buddy check), if my buddy hasn't already reached 2K and inquired of me. I know from experience that I always use more air on entry, descent, than I do on return, and tanks are often 2800 to 2900 once they're sbmerged and cool off, so we usually call the turn at 1800, unless we're doing shallow dives in an area where a surface swim is practical. (Your post would indicate a current, otherwise, call the dive and ascend now, instead of swimming to the rope). I was surprised with discussion in another thread, that some (many?) divers are unable to ascend without a guide rope. I had at least 35 dives in before I ever did an ascent WITH a guide line.
I don't expect an air integrated would change my current habits (which reflect my training), but having a display of estimated (key word that, ESTIMATED) air remaining could be educational. When diving with groups from my LDS, anyone returning under 500PSI, without having a burst hose or free-flow, etc, buy a round for EVERYONE on site. (Very few rounds ever get bought). And showing up for air with less than 500 in your cylinder had better come with an good explanation.
On the NDL side of the equation. My Oceanic will start adjusting the NDL almost as soon as I start an ascent. So rising from 90 feet to 60 feet, at the recommended 30fpm, will increase the NDL. The closest I ever pushed the computer was a dive briefed to 100 feet. I got down to 3 min remaining at a max depth of 102, by the time we had swum back to 70 feet, I was up to 6 minutes remaining and at 50 feet over 10 minutes remaining (air wise we turned at 1800 as briefed). That particular computer is very conservative, my wifes (buddy on that dive) computer never showed her under 10 minutes remaining. We did hang around the 30 foot mark for a bit before heading to 15 feet for our safety stop and added a bit of time there for good measure (since we had lots of air) and I surfaced with 800PSI.

 

[Doppler]

Just wanted to say something briefly about gas management and spgs... at least in the technical realm.

Please remember that the SPG is used for confirmation rather than information. A well-trained technical diver knows what her SPG is going to read BEFORE she looks at it.

Just figured since it's not been stated yet, somebody should.

 

[Warren_L]

Groundhog246 once bubbled...

Your examples make me wonder about your training and diving habits (no flame intended, I don't know you, only going by what I read). And someone else said "turn at 1500"!!! So 1500 out and 1500 back and on the surface with 0?

I would think that this would only apply to a uniform dive profile, so a turn around at 1500 isn't necessarily a bad thing. I've always been taught to do the deepest part of the dive first, and if this is the case, depending on your profile, 1500 as a turn around point might be fine.

But if it will take you the same amount of air to ascend as it does to descend, then definitely the rule of thirds.

 

[doole]

Doppler once bubbled...
Just wanted to say something briefly about gas management and spgs... at least in the technical realm.

Please remember that the SPG is used for confirmation rather than information. A well-trained technical diver knows what her SPG is going to read BEFORE she looks at it.

Just figured since it's not been stated yet, somebody should.

Thank you. Actually, IMO this ought to be true of every diver.

When instructing cw dives 2 through 4, every time we surface, I make a point of asking them: "Now without looking at your gauges, how much air do you have left?" By dive 4, they're getting it.

 

[SeaJay]

Tim Bits!

'Duffer... Thank you. I ate the whole box in one sitting.

How very cool is that?

What else do y'all have up there that we should be importing?