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Finless
05-09-2007, 10:42 PM
Due to many reasons (including weather, money and ill parents) I haven't had a dive since last September so I arranged a beginning of season shallow wreck (22 mtrs) dive for my club on 29th May.

We had a number of charter boat (a RIB in this case) novices + a number in the same situation as me so a shallow warm up dive was needed and I refused a few requests to go a bit deeper.

As is my wont I went in last and headed down the shot line on my own (aiming to find someone on the wreck when I got down there).

My first job was to deploy the anchor lift bag and send it up. I'd got the bag at the point where the anchor was starting to lift when I decided to swim out and back again to make sure I wasn't going to get caught on the chain or rope when I noticed I was ascending.

I dumped air and I flipped over and tried to fin back down but couldn't. At about the time where I felt my fins becoming loose because of the air in my dry suit feet I was becoming mightily concerned. I flipped over so I was heads up and tried to dump air as fast as I could but to no avail.

I managed a 4 minute dive to 21 mtrs and one swift ascent. Fortunately due to the very short time under water I suffered no noticable adverse affects. I think the problem was due to a stiff dry suit inflator that wasn't seating properly and was slowly allowing air into my dry suit + some "lay off rustiness".

Anyway, the point of my post is to remind you to check your gear out after a lengthy lay off from diving .......... ideally in a pool or somewhere shallow!

I think someone may have mentioned this fact to me in my formative diving years .......... about 10 billion times!!!

:rolleyes:

Quero
05-10-2007, 03:26 AM
... I'm quite new at drysuit diving. I was told that the emergency procedure for a runaway ascent is to lift the arms and let the air flow out of the wrist seals. I suppose this won't work if the suit has those zip-seal dry gloves attached, though.

Anyway, I'd be interested in hearing people's experience in using this arm-raising emergency technique. I noticed when I was last diving dry and taking photos that when I would lift the camera to shoot upwards (getting more light) some air did escape from the wrist seals.

The Publisher
05-10-2007, 04:56 AM
I raise my arms over my head all the time and air never leaks out.

I think your wrist seals may be too loose.

Zero
05-10-2007, 10:16 AM
Pull the neck seal. Vents more air quicker. If you have wrist mounted computers or compasses they will further restrict air flow.

Matt

Finless
05-10-2007, 10:18 AM
... I'm quite new at drysuit diving. I was told that the emergency procedure for a runaway ascent is to lift the arms and let the air flow out of the wrist seals. I suppose this won't work if the suit has those zip-seal dry gloves attached, though.

Anyway, I'd be interested in hearing people's experience in using this arm-raising emergency technique. I noticed when I was last diving dry and taking photos that when I would lift the camera to shoot upwards (getting more light) some air did escape from the wrist seals.

Hmmmm, I'm not so sure ............. I've never been able to that on my suit ... either on my wrist or neck seals ............ at least not without massively over inflating the suit.

You can yank open the neck seal if you are heads up and have time but that is not so easy when wearing gloves and if the suit has a neck collar and the seals are latex. Not to mention cold and wet ......... still, that's better than getting bent. My suit seals are the Manchette(sp?) style and they have a large contact area with the skin. The conical latex seals and the neoprene seals may be easier to grab hold of or disrupt the contact area with the skin?

Of course, in my case, I should have pulled the drysuit whip off the suit but I didn't figure out the cause of the problem until I was back on the boat.

It was a dumb thing to allow to happen but, once again, it demonstrates how fast things can happen and why I chose a shallow dive to get back into diving again. Had I access to a pool I would have gone in there before the dive.

Anyway, I have admitted my muppetry to the world and feel a better person for it. I just need to become a better diver again! The problem is that, because of my lay off, I am behind everyone else in dive preparation and all boat dives locally are deeper than I want to do until I have had a successful dive again ............. I may have to go and dive in a pond ......... oh God, NO!!!! :):):)

Quero
05-11-2007, 03:26 AM
I raise my arms over my head all the time and air never leaks out.

I think your wrist seals may be too loose.

Quite possible. I don't own my own suit, and my arms were getting wet up to the shoulders.


Pull the neck seal. Vents more air quicker. If you have wrist mounted computers or compasses they will further restrict air flow.

Matt

Good point about the comp/compass/bottom timer/etc., but probably only true if the seals fit properly to begin with, as noted above by Pub.

As to the idea of pulling the neck seal to dump air, is there a risk of getting a bunch of water into the suit which might drag you down to the depths as a consequence?


Hmmmm, I'm not so sure ............. I've never been able to that on my suit ... either on my wrist or neck seals ............ at least not without massively over inflating the suit.



I see what you mean, but by definition, a runaway ascent would seem to represent a massive overinflation of the suit, wouldn't it?

Finless
05-11-2007, 09:57 AM
Quite possible. I don't own my own suit, and my arms were getting wet up to the shoulders.



Good point about the comp/compass/bottom timer/etc., but probably only true if the seals fit properly to begin with, as noted above by Pub.

As to the idea of pulling the neck seal to dump air, is there a risk of getting a bunch of water into the suit which might drag you down to the depths as a consequence?



I see what you mean, but by definition, a runaway ascent would seem to represent a massive overinflation of the suit, wouldn't it?

No ....... not really .......... you only need to let it get a little bit too far in front of you and away you go. Particularly in the shallower depths where the pressure change is greatest and the expansion of the gas in your suit is greatest!

Quero
05-11-2007, 01:00 PM
No ....... not really .......... you only need to let it get a little bit too far in front of you and away you go. Particularly in the shallower depths where the pressure change is greatest and the expansion of the gas in your suit is greatest!

I know how that is. On my first open water training dive in a drysuit (already with an instructor rating, BTW), I had an ascent when I came up to make a safety stop and couldn't dump the air fast enough. The dump valve was purging too slow (the instructor had told me to dial it closed a couple of clicks on the bottom so that it wouldn't be constantly bleeding out air), and jamming on it didn't help enough, as far as I could tell. Colleagues of mine here on Phuket who are drysuit trained from their home countries told me about the arm-raising thing. I'm not in a hurry to test it out, though! OTOH, I'm pretty sure I'll buy my own drysuit so that I don't dive "wet" in one again.

Finless
05-11-2007, 01:10 PM
I know how that is. On my first open water training dive in a drysuit (already with an instructor rating, BTW), I had an ascent when I came up to make a safety stop and couldn't dump the air fast enough. The dump valve was purging too slow (the instructor had told me to dial it closed a couple of clicks on the bottom so that it wouldn't be constantly bleeding out air), and jamming on it didn't help enough, as far as I could tell.I use a cuff dump so when I'm ascending it looks a bit like I'm giving a Nazi salute all the time! :) Perhaps, after you had fully opened your auto dump you needed to spin round to get the gas up to your shoulder?


Colleagues of mine here on Phuket who are drysuit trained from their home countries told me about the arm-raising thing. I'm not in a hurry to test it out, though! OTOH, I'm pretty sure I'll buy my own drysuit so that I don't dive "wet" in one again.It is not an ideal thing to have to do but it is much more preferable to rapidly ascending if you still have deco to do ...........

Dry suits just take a bit of getting used to ........... this was the first rapid ascent I've ever had during a "proper dive" ........ ordinarily I like to come up nice and slowly (max 9 mtrs a min).

Oh well, I'll do better next time.

amtrosie
05-11-2007, 01:52 PM
As far as this particular post goes I find it best to set the auto dump a few "clicks" from full open. I have never had any real issues, but my first response to any PERCIEVED problem is to disconnect the inflator IMMEDIATELY!!! This I do all the time.

On a seperate note and getting back to the point of the post of checking gear before diving, after a lay-off. I preface all this by saying that this is not directed at Finless. In my years of maintaining scuba gear, aircraft, and cars I am continually dealing with people that refuse to perform preventitive maintenance on their equipment. There is a parallel here, the less the life sustaining equipment (esp. scuba and airplanes) is utilized the more the owner refuses to maintain it! Within the aviation industry, most maintenance performed is preventitive in nature. My personal solution for this problem is to first call it what it really is....PREVENTIVE MAINTENANCE. The perception that the less it is used the less maintenenace (service) is needed. In reality the very opposite is true, the less used, the more maintenance required.

This may be a small distinction, but an important one. In saying it repetitively the actual meaning starts to take root. Again this is not a rant directed at anyone, especially Finless. It is just that his post has prompted me to address this here. Rather, I want to applaud Finless for his self revelation. It is not easy to admit a failure and it is the real man that does so.

Safe diving to every one, after your gear has been serviced, to prevent an unwanted trip to the local chamber.