Inexperienced or just stupid?

[robandliza]

Hi

After fairly recently joining SB and reading all the advice on here, I'd like to share an experience and get your comments as to whether or not I was very stupid

Sorry for being so long

I qualified only last year and did my first dives without an instructor holding my hand in May this year in Clearwater
I buddied up with a guy with a lot more experience and was more than happy on that front and rented everything except mask,fins and computer

The details from my dive computer are in metric but I'll add imperial measurements

First dive
Started with 320 bar (3200psi)
Max depth 17.7m (58 ft) Ave depth 15.7m (51ft)
water temp at bottom 23c (73F)

I was regularly checking my air but then noticed it seemed to be at 100 bar (1000psi) for a while, when it suddenly jumped to 25 bar(250psi) when I'm still at 15m( 50ft) after 45 mins
I must have a good mask as it didn't smash when my eyes flew out of my head straight into it!!!!...I'm not too proud to say I s**t myself( not literally, honest) but I didn't panic. I grabbed my buddy, showed him the gauge and we started ascent making sure I was within touching distance of him all the way. He told me afterwards he was worried I wasn't going to stop but I did stop at 5.5m(18ft) at 48 mins. I did 3 mins there before surfacing with 20bar (200psi) showing

Now for the stupid(?) bit

Second dive after an hour of SIT

Again started with 320bar

Hit max depth of 13.4m (44ft) early in the dive. I was checking air more this time considering what had happened previously but after about 5 mins I noticed my air had not moved but let it pass. I kept checking and it still hadn't moved after about 10 mins, so I knew it was stuck. I pointed out to my buddy who asked if I wanted to go up, but I said no, I'd be ok..

Is that stupid?..my thinking was that I'd averaged 50 ft and lasted 50 mins previously. I thought if I stayed shallower than that ( actually averaged 35ft this time) I should be able to last at least 50 mins, but would still play conservatively and cut dive before then
I didn't want to ruin my buddy's trip and at the time it was going to be my only 2 dives of the year ( now going back out next month to Key Largo) so didn't want to lose out
Also, I knew(did I?) that I had 320bar(3200psi) to start otherwise the gauge wouldn't have got up there to start with(right?)
I kept a close eye on time and started ascent to a safety stop after 38 mins. Total dive time was, inc stop, 46 mins. The gauge immediately dropped to 1000psi when I got on the boat to show the Capt that there was something wrong with his equipment

I know I could have lost a lot more, but just how stupid was it. At the time I thought I was using some common sense, but the more I read on here the less I believe it

Your comments would be much appreciated

Rob

 

[RJP]

Your comments would be much appreciated

Rob

If the computer was that far off at 25bar at end of dive 1, how do you know it was right at 320bar at the start of dive 2?

Fact of the matter is, once you knew the computer was that screwed up (after the first dive) you really should not have been diving it on the second. When you confirmed (on the second dive) that it was STILL screwed up you should have thumbed the dive.

 

[Blox]

I agree with RJP.

I wouldn't have done a second dive with an SPG that had proven to be unreliable.

 

[Charlie99]

It turns out that you did indeed correctly analyze the situation, but what tends to hurt us is what we don't know. With only 2 dives outside of class, making the judgement call to proceed with the dive seems to be well beyond your experience and understanding.

Were I in your shoes, I would reflect upon whether my decision was unduly influenced by fear of letting down my buddy, and resolve to have to self control to err more on the side of safety in the future. It's clear from the thread title that you are doing the needed introspection. Making the decision to cancel a dive can be very difficult, but is important to have the mental discipline to be able to do that at times.

Correctly analyzing the situation and having a positive result can be either an indication of a good decision or just being lucky. At your experience level, IMP this incident falls more into the luck category.

Charlie Allen

 

[Colliam7]

Rob: Two thoughts: 1) I would tend to agree with those who suggested not doing the second dive, or calling it early. I wouldn’t call your behavior stupid, just something that you may want to rethink for the future. a) Part of my reasoning involves a ‘fairness factor’ for your buddy, who may have had to alter the plan of his/her dive, to accommodate your situation, twice. After the first dive, if you elected to forego the second, your buddy could possibly have teamed up with another person or a pair, etc. Not a big deal, but something to think about in the future. b) The profile you describe for the second dive was not an envelope pusher – you may even hear Caribbean DMs refer to a ‘50 ft for 50 minutes’ dive, a ‘50/50’ dive, as a safe, relaxing warm water profile with an AL 80. Nonetheless, the considerable benefit of hindsight suggests it was probably not the wisest decision, to go ahead with the second dive, given the data you had indicating the gauge was unreliable during the first dive, and given your relative newness to diving (with associated lack of personal experience to gauge your air consumption patterns). The problem was, you had no way of knowing just how unreliable the SPG was. As RJP noted, how did you know if it was ever accurate, even if it seemed to read correctly at the start of the dive? Now, if you are Mike Nelson, on Sea Hunt, diving with a J valve (reserve access lever) you may be able to go forward without a SPG. Even at moderate depths like the Keys, I probably would not have done so, but that, again, is hindsight. 2) Relatively early in your diving adventure, you have had a very valuable learning experience and come back safely to tell about it. You have experienced a lesson about: a) dive planning – make sure you and your buddy have signals worked out before the dive; b) pre-dive safety check – make sure you understand the potential pitfalls of rental equipment, and equipment in general; and check your gear to the best of your ability; c) developing a basis for evaluating your personal dive profiles as you accumulate experience - logbooks offer spaces to note your beginning and ending pressures. More than a few people never fill those in – as long as they got back aboard with at least 500 psi, their reasoning is, ‘Who cares?’ We have become so dependent on computers during a dive, yet often fail to go back and either download or transcribe some valuable data from them, that makes computers such useful tools. Well, just using a logbook, you can go back and organize your experiences, using data such as total time, max depth and air used, along with environmental factors such as current (Y/N), temperature, and begin developing a pretty good idea of you personal dive profile. Are you a 50/50 diver, or are you a 50/40 diver, or a 50/60 diver, for example. Are you a 50/30 diver now, and you evolve to a 50/60 diver as you gain experience? So, use your logbook, it is your personal journal, or diary, not just a place to check off dives.

Your willingness to share the experience, and openly ask for input on your decision-making, is a very positive step. Keep learning, and keep diving.

 

[Damselfish]

Something went wrong on the first dive and you handled it well. But, I probably wouldn't have done a second dive with an unreliable pressure gauge. (Even though I am experienced, have a very good idea of my air consumption, and usually come up with half a tank anyway. Even less of a good idea when you're new and don't have these things nailed down yet.)

If the pressure gauge was busted, you don't know for sure what was in your second tank to begin with. Now, you could have confirmed that by checking with someone else's guage. And if it checked out you might have gone on the second dive hoping that was a fluke, and bailed when you noticed the needle wasn't moving. But I wouldn't really recommend it.

Also, sounds like you didn't point out the gauge problem until after the second dive? If not, might have been worth mentioning to the captain sooner. Sometimes they will have some spare gear on a boat, or gear from someone who is not doing that dive. (Then again, he might have said no working gauge no dive, which would have been a fine thing too.)

 

[robandliza]

Thanks for all the input

You've pretty much all confirmed my thoughts. If it happens again I will cut the dive

Damselfish
I did mention the SPG to the captain, as did my buddy as he, being the more experienced checked it as well as he was at or around 1000psi. He was surprised(jealous?!!!) to see me at the same level...but not as surprised as me a few moments later!!!!
Can't remember what the Captain said to be honest, but it certainly wasn't " no more dives for you"

Well these things are sent to try us and I'm still here with a bit more knowledge than previously

Thanks again

Rob

 

[GrumpyOldGuy]

I may be confused, but I think 320bar is about 4600psi. Am I missing something or are you diving really high pressure tanks?

 

[TSandM]

I think almost everybody is going to agree that you shouldn't have gotten back in the water with a malfunctioning gauge, and that once you did and proved it was again malfunctioning, your dive probably should have been over at that point. The reasons, as already stated, are that at your level of experience, you can't be very sure of your gas consumption (the very fact that you're diving without a gauge could have caused your gas consumption to go up, just through being nervous) AND that the likelihood of you executing a smooth, stress-free air-share in the event you miscalculate may be low. Having been in the position of having to call a dive for three other divers, when all of us had paid significant sums for the trip, I know how hard that is. But being honest with yourself is a very important lesson for a diver.

What I found interesting about this post was to ask myself what I would do if I were in your position. Although I would NOT have gotten back in the water with the malfunctioning gauge (no DM or crew would have talked me into doing that), I could imagine being in the position of having a gauge stick, and becoming aware it was sticking and not registering my consumption. What would I do then?

Given that I have several hundred dives worth of gas consumption data (and Colliam, that is a wonderful post about the value of recording and analyzing that information) AND I always dive with a buddy who maintains adequate reserves for ascent AND we practice air-sharing regularly, I think I would probably have gone on to execute a fairly conservative length dive, just as you decided to do. That's not the safest answer, but it's what I would do.

Anyway, thanks for asking the question, because it's one we can all probably benefit from considering.

 

[RowingMunkeyCU]

I may be confused, but I think 320bar is about 4600psi. Am I missing something or are you diving really high pressure tanks?

agreed, i believe 1 bar = ~14.5 psi

so at 320 bar you would've been at about 4641 psi
or at 3200 psi you would've been at about 221 bar