One stupid thing I did that new divers should avoid

[Juardis]

For my 100th post, I thought I'd share a stupid thing I did that could have ruined my dive vacation, or, at worst, put me into a deco-dive without me even knowing it until I got a DCI hit.

It was my 7th and last dive of a 3 day diving trip in West Palm Beach. It was also our deepest dive down to 90' so I could complete my deep diver specialty. We were also diving Nitrox.

I have a Suunto D6i computer (wrist mounted) that I wear as a watch, face on top of my wrist. My usual procedure is to take the computer off, put my wet suit on, put the computer back on so I don't lose it, then put my BCD on. Of my 25 dives, I've inadvertently activated the DIVE mode on my computer while putting on my BCD about 24 times. The face is so large that it typically gets hung on my shoulder strap as I'm getting into my BCD, which causes the upper right button to get depressed, which causes the computer to enter DIVE mode. I hear the beep, so I know it's happening, but it's OK since it'll either exit DIVE mode after 5 minutes or I'll put it back in TIME mode myself. Well, what happened on my very last dive of the trip was that not only did the computer enter DIVE mode, but I also inadvertently changed it from DIVE-NITROX to GAUGE. To change the type of diving, the lower right button needs to be pushed immediately after depressing the upper right button, i.e., immediately after entering DIVE mode. You see, there are 4 types of DIVE modes you can enter - AIR, NITROX, GAUGE, FREE. If you dive NITROX, you can't go back to AIR until the no-fly time has counted down to zero. If you dive GAUGE, you can't go back to anything. You're stuck on GAUGE for 48 hours, which is the time the no-fly time takes to countdown to zero after finishing a GAUGE dive.

For those that don't know, GAUGE is tech diving where you intentionally ignore all these safety limits and dive as deep as you want, as long as you want. You may enter deco, you may not, but the computer doesn't harrass you with safety stops, or count down your no-deco dive time, or really much of anything except give you depth, ascent rate, and dive time - all very useful stuff mind you, but not what you want when you're trying to keep from going into a deco dive or trying to maintain your 3 minute safety stop (or any additional time you might incur if you happen to have gone into a deco dive).

Back to my story. On the surface I activated my computer, saw the battery was OK, but failed to see I was in GAUGE mode. So I disembarked the boat and descended. When I got to the bottom, I noticed my stop watch was on, which is a feature my D6i allows while in DIVE-AIR and DIVE-NITROX modes. But I was preoccupied with navigation, keeping up with the dive leader as we headed to the reef, and keeping up with my buddy, so I didn't think anything else of it. Once at the reef a few minutes later, I checked my instruments and computer and noticed I was still in what I thought was stop watch mode, which of course I wasn't because I was in GAUGE mode and the only thing displayed IS a stop watch. So I tried unsuccessfully to remove the stop watch from the display and get back to what is normally there for a few minutes, then gave up and went back to enjoying my dive.

Long story short, since it was my first deep dive ever and I was a bit stressed about the stop watch thing, being as deep as I've ever been, and swimming hard to keep up with the DL at the beginning, so my air was depleted very quickly (20 minutes, which is short even by my air hog perspective). After 22 minutes I began my ascent with my buddy, which luckily for me was my wife, but I had no idea what my no-deco time was or how long my safety-stop should have been once I ascended above 20 ft because my computer never told me. I had to rely on my wife to tell me when she satisfied her safety stop time limit. Only when I got on the surface and had time to think about what was going on did I figure out I was in GAUGE mode and couldn't change the mode for 48 hours.

So anyway, here's one lesson. Ok, 2 maybe.

1. if you wear a wrist computer, either keep it off until you get your BC on OR turn it so the face is on the underside of your wrist as you put your BC on.
2. MAKE SURE YOU ARE IN THE DIVE MODE YOU THINK YOU SHOULD BE IN WHEN YOU ACTIVATE YOUR DIVE MODE. This means intentionally activating DIVE mode on your computer and paying attention to which mode you're actually selecting - AIR, NITROX, GAUGE, or FREE.

As it stood for me, I would not have dove again with my computer in GAUGE mode. Others might have, but I would not. I am not experienced enough to disregard my computer. Thankfully I was not diving again this particular trip. Hope this helps others.

 

[antattack]

Good news- if your managed to get out of the water without leaving the dive tables, you could have dove all week. Just figure out your NDL and dive tables. Diving the tables is easy and fun

 

[g1138]

Very good advice. I normally have to turn my wrist gauges to face the inside of my wrist when suiting up, otherwise it catches on everything.

Now as for your 100th post, normally it's customary to post naked. Probably best to wait till you're out of the office

 

[tracydr]

So, did you actually get DCI or just feel like you could have gotten it? Which dive of the day was this? Because 90 feet for 20 minutes, if it's the first dive of the morning wouldn't be much.
Did you learn how to use tables?

 

[Searcaigh]

This post justifies the mandatory use of tables for training purposes and providing an essential back up should a computer malfunction or as in this case be wrongly set for the dive.

I hope that you did not get a "hit" and that you learn from this experience.

 

[Mike2Fst]

For those that don't know, GAUGE is tech diving where you intentionally ignore all these safety limits and dive as deep as you want, as long as you want. You may enter deco, you may not, but the computer doesn't harrass you with safety stops, or count down your no-deco dive time, or really much of anything except give you depth, ascent rate, and dive time - all very useful stuff mind you, but not what you want when you're trying to keep from going into a deco dive or trying to maintain your 3 minute safety stop (or any additional time you might incur if you happen to have gone into a deco dive).

Juardis,

Not the best description I've heard about Tech Diving. Guage mode is a mode to disable all functions except time, depth and ascent rate, not to ignore all other aspects of the dive as you imply, but to establish a back up depth guage and timer to follow your dive plan which is well written on a slate should your primary/secondary dive computers fail. I dive with 2 Shearwaters as primary and secondary, but I also have a Uwatec Aladin 2G in guage mode as a back up depth guage and timer. Call me paranoid, but there is room on the arm for it and you never know when Murphy has decided to be a part of the team.

 

[Jim Lapenta]

"For those that don't know, GAUGE is tech diving where you intentionally ignore all these safety limits and dive as deep as you want, as long as you want. You may enter deco, you may not, but the computer doesn't harrass you with safety stops, or count down your no-deco dive time, or really much of anything except give you depth, ascent rate, and dive time - all very useful stuff mind you, but not what you want when you're trying to keep from going into a deco dive or trying to maintain your 3 minute safety stop (or any additional time you might incur if you happen to have gone into a deco dive)."

This is completely false. Gauge mode is used any time you only need the required info to back up another computer or to provide the necessary information to follow the dive plan you should always do regardless of whether you use a computer or not. Relying on a computer to tell you when your NDL's are up, when to ascend, when to do a safety stop and for how long, and to prevent you from going into deco is a good way to get hurt. Your brain tells you all those things based on the plan you should come up with and the gauge mode provides the info needed to follow that plan. You do not need a computer to do recreational dives and in fact I recommend new divers not get one. Just for the reasons seen here. Too much reliance on it. It promotes what I consider to be reckless behavior on the part of the new diver. I want new divers to know how much time they have and decide for themselves when it's time to come up. Not wait on a computer to tell them.

There was no reason you could not have used the gauge mode to do the entire dive as a new diver. Divers are shown how to plan dives, monitor ascent rates, and keep track of their NDL's for a given depth. Or they should be even if learning with a computer. That would just be common sense to most divers. Computers fail. A watch and depth gauge and tables as back up is all that is needed to finish the dive and plan subsequent ones.

And it not a matter of experience at this level. It's about having the basic information passed on to you to allow you to deal with situations like this. A dead comp or one in gauge mode is no reason for a diver to cancel any subsequent dives unless the NDL's have been exceeded. It may require a longer surface interval than was planned for but no reason to stay out of the water for 2 days.

And one other thing. If this was a planned deep dive as part of course I am very dismayed to see that it appears it was not really planned. It seems like the plan was go down to 90 feet, watch til the computer says it's time to go up, and then do so. What was the gas management plan? What was the test or task to check for narcosis? What was the contingency plan? What did the instructor say about this episode? Did you have a written plan and back up method of following it?

 

[Sunny2012]

Wow, bummer. Looks like the D6i has extended buttons that I could see would easily get bumped. My older Suunto Mosquito seems much easier to use and the buttons are somewhat protected. I wear it as a watch and it goes into dive mode with I hit the water... No muss/no fuss or need to change anything and easily allows me to download my dives to my Mac.

Will consider your input when I am looking for a new dive computer.

Glad you are ok and safe diving!

 

[Lorenzoid]

I know what you mean about the computer (D6 in my case) getting hung up on the BC straps. I prefer to put my computer on before my BC for the same reasons as you--not losing it. Fortunately, it has never inadvertently had its buttons pushed. I tend to put it into Dive Mode manually before I get into the water and look to see that it says Nitrox/Air--I have to believe that I'd notice it was in Gauge Mode.

p.s. I knew you'd catch flak for that description of Gauge Mode.

 

[BluewaterSail]

I disagree with the definition of guage mode that the OP provided, which leads to another lesson learned.

I think of gauge mode as all of the information that you need to do a safe dive, given that you have planned the dive. It doesn't mean that you now won't be bothered with safety stops and NDLs, it means that you don't need the machine to tell you about them. Seeing average depth, max depth and current depth, and of course time, actually gives me a better picture of my situation than when I used a computer. I generally dive 32%, and I have memorized the conservative max bottom times that I have for various depths that I often dive. If I want to do repetitive dives, or I can only get air, I check the tables which are always in my dive bag. I know what my plan for the ascent and safety stop is. So its easy.

I have never done a technical dive, but I switched to a bottom timer (equivalent to a computer in gauge mode) six months ago, and I am very comfortable with it. More comfortable than I was being told by a computer what to do, which often led me to not bother paying attention to the details myself.

I would like the OP to consider another lesson learned:

A computer can let you down, like any peice of electronics. So, just like we practice taking off our mask underwater, so if its kicked off we can handle it, practice thinking through underwater what the situation is, given depth or average depth and time. How much time do you have left before you need to begin your planned safe ascent? Do scenarios in your head on land. I find the more I do what-if's, the easier it is to handle actual occurances.

Let the computer be a backup for what you already know.