DIR, s-drills, consistency, and AI computers

[kanonfodr]

I guess I should have clarified in my first post: my computer stays in gauge mode, I simply use it as another source of information and for recording of my dive data including air consumption.

rongoodman: I was trained to show the SPG as Don stated, that's why I started the thread.

TraceMalin: Appreciate the insight, especially the part about using my transmitter on my right post when I move to doubles.

Sloth: I've been meaning to hook up with Jo and Matt at IDH, but I'm rarely down in that part of the island and thus it's never been convenient. I do stop in regularly at their Hickam shop and they say they will be offering Fundies soon, as I believe Matt is going for his GUE Instructor this month.

Jax: Thanks for the firsthand experience tip. Neither of my Essentials classmates had a problem with it when I tried it as an experiment.

PfcAJ: I appreciate your anecdote and I'm glad you both got out well and good. As far as computers I hope I clarified that above.

Don: Thank you for the reasons why AI computers aren't DIR. By robust do you mean to say that the device can suffer physical damage from depth (ie, case cracking)?? Batteries go out, but that's why you keep them handy for quick swap (mine are diver replaceable).

TSandM: I like how you correlated this particular subject to vehicle speedometers and it makes a lot of sense. Especially since my SPG is color coded. Never thought about it like that, I must say.

Thanks for all your input so far, everyone.

Peace,
Greg

 

[Guy Alcala]

I second the person who said that a computer is often difficult for another diver to read. Analog displays like SPGs are much faster to comprehend (this has been studied, and is the reason why cars almost never have digital speedometers). For this reason, even if you ARE using an AI wrist computer, I'd show the gauge.

Do recognize that, since you put this in the DIR forum, AI computers are not recommended by any agency teaching a "DIR" style of diving.

While I agree that digital speedometers are a pain, Bret Gilliam in his book "Deep Diving" mentions that digital depth gauges are much easier to read, especially if narced. ISTM how quickly the information is likely to change and how precise it needs to be determines whether a digital or analog gauge is best. For quick reading I prefer the analog SPG, but for precision a digital one is better. And every DIR-diver I've ever seen or talked to has used a digital depth/BT instead of analog gauges.

I use an SPG, a digital computer and an analog watch, with an analog depth gauge carried in a pocket for backup. I'm not a fan of Uwatec's digital ascent rate readout or even sequential rectangular segments on the newer Suuntos and many other computers, much preferring the simple swinging arm (3 o'clock max. rate, 1:30 too fast, 4:30 slow but acceptable) on my old Suunto Favor. My analog watch with rotating bezel gives me a better intuitive feel for about what point of the dive I'm in, while the digital dive time readout on my computer requires less mental processing to determine the exact value.

All that being said, I do think there is a place for wrist-mount AI. The main reason I went with wrist gauges was because I had all the information concentrated in one or two places, which I never had to search for and which were usually in my line of sight. Consoles often required a little searching. Having pressure included in my primary instrument just carries that concentration to its logical conclusion.

Certainly, a transmitter provides an increased snagging hazard and an additional failure point, which may cause you to leave it behind on some dives (note that I'd never consider not having the SPG along as well), but it also provides personal redundancy. While AI may not be officially DIR, I notice in the 2008 Halcyon catalog that there are several photos of Casey Mckinlay (I believe) in a cave wearing doubles and stages, along with a Galileo Sol on his right arm, a Tec 2G and mini compass on his left, and a digital watch on his left wrist; I imagine he also had an SPG on his left hip. I suspect those at the top of the mountain may be less dogmatic about AI than DIR-types lower down the food chain.

I've often seen it stated that you don't need personal redundancy because your DIR buddy provides that. If so, why are so many open water DIR dives done in smallish doubles with all the extra failure points they introduce (several extra O-rings, two additional valves, the manifold, and an extra first stage), when a large capacity single tank is far simpler, lower drag and has far fewer failure points?

Guy

 

[Sloth]

For quick reading I prefer the analog SPG, but for precision a digital one is better.....

What scenario requires you to need to have a precise measurement of how much gas you have? 100psi is as granular as you ever will need to be. Showing a dive buddy an unfamiliar wrist display to show PSI only causes confuses.

And every DIR-diver I've ever seen or talked to has used a digital depth/BT instead of analog gauges.

You will rarely if ever need to show a team member your depth gauge so the type of depth gauge used has no impact on the team.

All that being said, I do think there is a place for wrist-mount AI. The main reason I went with wrist gauges was because I had all the information concentrated in one or two places, which I never had to search for and which were usually in my line of sight. Consoles often required a little searching. Having pressure included in my primary instrument just carries that concentration to its logical conclusion.

Why do you need to have PSI cluttering your display? This is DIR remember, brain is primary instrument, your pressure gauge is just to check that you are tracking gas consumption correctly. I dont see a scenario for an experinced diver - be it a tech diver or some DM on a cattle boat - to need to check their actual PSI more then a few times. PSI on your depth gauge just adds clutter.

....While AI may not be officially DIR, I notice in the 2008 Halcyon catalog that there are several photos of Casey Mckinlay (I believe) in a cave wearing doubles and stages, along with a Galileo Sol on his right arm, a Tec 2G and mini compass on his left, and a digital watch on his left wrist; I imagine he also had an SPG on his left hip. I suspect those at the top of the mountain may be less dogmatic about AI than DIR-types lower down the food chain.

Wasnt the WKKP doing real world stress testing for Uwatec? What purpose does an AI computer serve for a cave diver doing stage diving that rarely touches his backgas? Do you really think any one diving with the WKKP really needs to rely on a AI computer? It's a toy, its not a tool in the toolbox.

I've often seen it stated that you don't need personal redundancy because your DIR buddy provides that. If so, why are so many open water DIR dives done in smallish doubles with all the extra failure points they introduce (several extra O-rings, two additional valves, the manifold, and an extra first stage), when a large capacity single tank is far simpler, lower drag and has far fewer failure points?

this has been covered so many times that I not going to bother.

 

[PfcAJ]

Shouldn't all this be in a hog forum or something?

AI computers simply are not DIR, let's not try to shoehorn them into a faux DIR just to make everyone happy...

Guy, those pics you refer to were part of a test for uwatec. The diver was on an RB80 being run by drive bottles, not much backgas usage there Also, mant folks dive doubles in relativly shallow water because of their stability, weighting (drysuit), and options they afford the diver underwater.

 

[PfcAJ]

Shouldn't all this be in a hog forum or something?

AI computers simply are not DIR, let's not try to shoehorn them into a faux DIR just to make everyone happy...

Guy, those pics you refer to were part of a test for uwatec. The diver was on an RB80 being run by drive bottles, not much backgas usage there Also, mant folks dive doubles in relativly shallow water because of their stability, weighting (drysuit), and options they afford the diver underwater.

 

[Trace Malinowski]

Showing a dive buddy an unfamiliar wrist display to show PSI only causes confuses.

Why do you need to have PSI cluttering your display? This is DIR remember, brain is primary instrument ...

Can you really trust a primary instrument that can't read a gauge?

Sloth, I'm just joking.

You will rarely if ever need to show a team member your depth gauge so the type of depth gauge used has no impact on the team.

While Sloth didn't mention it, the gauges are usually checked for accuracy at the start of the dive and teams will elect which team member's gauge to go by - usually the leader's. So, if the leader's reads 10 feet and mine reads 12 feet, I know that I need to adjust at each stop. Accuracy is a bigger problem when one gauge is calibrated to sea water and another to fresh or when a diver is wearing an analog. As Sloth said, the only time I've shown a gauge during a DIR dive, other than at the start, is when it crapped out. The team leader became my depth gauge.

Kanon, AJ is right. Since this is the DIR forum, strike what I told you about using your gauge at all. I figured since you had it and were probably going to use it while you pursued this philosophy, until you upgraded to philosophy-compliant gear, you might get some use out of it. But, your transmitter will be problematic as would showing your gauge to others. For new divers, doing everything by the numbers is one of the keystones to learning without allowing bad habits to creep into the system. The instructor in me always seeks ways to use the tools in the enviroment, including the equipment used by students, as a means by which individuals and teams can learn to think, but I wasn't advocating your AI computer as being in anyway DIR philosphy-compliant. The redundancy I mentioned was just a way of getting some value out of it, though, unnecessary.

 

[TSandM]

Just to add a comment on this thread . . . for a variety of reasons that I won't go into, I was in the water with a newer diver today who was briefly diving some borrowed equipment for demonstration purposes. He was distressed because the pressure gauge (which was a Suunto Cobra) was clipped off to his waist strap, and he couldn't figure out how to get it loose. So I came over and checked his pressure for him (which was really unnecessary, as we were in 15 feet of water for less than 10 minutes). I found myself trying to read the screen on the Cobra with it upside-down, and with the pressure numerals being the smallest ones in the display, and it was really irritating. Grabbing an analog SPG, I wouldn't even have had to look at the numbers. I could just have looked at where the needle was on the dial, and that would have been enough.

 

[lamont]

Warning -- noob, non-dir diver post . . .

I just got an air integrated computer. Even though my buddy knows the computer, he still doesn't quite "get it" (locate and read the air display) when I show my computer.

One glance at an SPG, however, causes immediately and clear understanding, no matter who you are. It seems this would be important in the highly-skilled environment in which you dive.

Yup, I've been 'shown' an AI computer before and it produced a response of "uhhhh.... 4 digit number... how do i read big numbers again? does that look right?" -- and I wasn't even all that narc'd at around 40 feet...

OTOH, an analog gauge in the red is super obvious...

 

[lamont]

Certainly, a transmitter provides an increased snagging hazard and an additional failure point, which may cause you to leave it behind on some dives (note that I'd never consider not having the SPG along as well), but it also provides personal redundancy. While AI may not be officially DIR, I notice in the 2008 Halcyon catalog that there are several photos of Casey Mckinlay (I believe) in a cave wearing doubles and stages, along with a Galileo Sol on his right arm, a Tec 2G and mini compass on his left, and a digital watch on his left wrist; I imagine he also had an SPG on his left hip. I suspect those at the top of the mountain may be less dogmatic about AI than DIR-types lower down the food chain.

They do a lot of testing. Just because a picture catches JJ or Casey diving X or Y gear doesn't imply a particular gear endorsement...

(And yes, they're less dogmatic, but that doesn't mean that anything goes...)

 

[kathydee]

During an S drill, when it comes time to show the OOG diver your SPG, is it a real procedural no-no to use your wrist mounted computer instead of unclipping the SPG? Peace, Greg

Hi Greg,

Your post sparked the memory of when I was auditing your Essentials class & I asked how much gas you had left. You showed me that wrist gauge.

I remember a lot of unfamiliar digital numbers, but it's been quite a while since I dove with non-DIR diver so I had no idea what you were trying to communicate .

Instead of trying to figure it out, I just looked directly at the SPG clipped on your left hip D ring & found my answer in 2 seconds .

The point is that standardization is simplification - if you are diving this system you just get use to certain things from your buddies & their gear and the rest is a complication that takes unnecessary effort to figure out-- especially under stress.

Enjoy that warm water !