GerryO
09-06-07, 22:18
Heard a wee whistle from the medium pressure inflator hose on my BCD a few dives back. Twisted the hose, shot some air in, twisted hose again and it stopped. Fine. Nothing to worry about. I -nearly- always rinse my gear out in fresh water after using it and make a point of doing a self-test and a buddy check before getting in the water, so there couldn't be a problem with the jacket. I only use the BCD at the surface, controlling my buoyancy with the dry suit throughout the dive and I never touch the inflator until I am back at the surface.
So, there I was down in the cool, spooky dark of Conger Alley –Friday 8th 22:30- at twenty seven meters and loving it, but feeling a touch floaty. No problem, just dump a wee bit of air from the suit and continue the dive.
I keep feeling a bit floaty and dumping more air from the suit. I even check my weight pouches, but they are both still there, so that's not the problem. At about fifteen meters I pick up a big chunk of rock and this seems to stabilize things. By the time I get to twelve meters I am juggling three rocks, still feeling floaty and have signaled to Robert that I am thumbing the dive.
At about seven meters I could have picked up Beryl the seal and I would still have been heading for the surface.
I blew out, hard, thinking that it would curtail the ascent- no chance. I was then amazed to hear the over-pressure valve on my jacket start to fart out large amounts of air. Where in the name of the wee man did that come from? I mean, I didn't put it there.
It turns out that the inflator has been squeezing air into the jacket for the whole dive. When I got above ten metres Boyle's law kicked in, doubling the volume of air in the jacket and sending me surface-wards. The thing that I am kicking myself about is that I knew by buoyancy was problematic and did not check the jacket . That option was closed off in my mind because of my normal diving practice of relying on my suit for buoyancy.
Anyway, here's my learning for the night- if I am having buoyancy problems check the following:-
1. Suit dump valve
2. Weight pouches
3. BCD dump valves
4. Suit direct feed.
5. BCD direct feed.
My "closed" mindset meant that I only addressed point 1, 2 and 4.
Also, remember that little hiss I mentioned at the start of this, well when Stewart opened up the direct feed inflator button it was a mass of green gunge and verdigris. So, if you discover a little niggle with your kit, it might merit more than twist, twist squirt!
I was very lucky last night, if I had encountered the same problem on the thirty and forty metre dives that I was doing last week the outcome would have been very different.
That's me then, I just wanted to share this incident with you to raise awareness of how being trapped in a certain way of thinking can have serious safety implications.
Gerry.
Originally posted on CUSAC.org safety forum
So, there I was down in the cool, spooky dark of Conger Alley –Friday 8th 22:30- at twenty seven meters and loving it, but feeling a touch floaty. No problem, just dump a wee bit of air from the suit and continue the dive.
I keep feeling a bit floaty and dumping more air from the suit. I even check my weight pouches, but they are both still there, so that's not the problem. At about fifteen meters I pick up a big chunk of rock and this seems to stabilize things. By the time I get to twelve meters I am juggling three rocks, still feeling floaty and have signaled to Robert that I am thumbing the dive.
At about seven meters I could have picked up Beryl the seal and I would still have been heading for the surface.
I blew out, hard, thinking that it would curtail the ascent- no chance. I was then amazed to hear the over-pressure valve on my jacket start to fart out large amounts of air. Where in the name of the wee man did that come from? I mean, I didn't put it there.
It turns out that the inflator has been squeezing air into the jacket for the whole dive. When I got above ten metres Boyle's law kicked in, doubling the volume of air in the jacket and sending me surface-wards. The thing that I am kicking myself about is that I knew by buoyancy was problematic and did not check the jacket . That option was closed off in my mind because of my normal diving practice of relying on my suit for buoyancy.
Anyway, here's my learning for the night- if I am having buoyancy problems check the following:-
1. Suit dump valve
2. Weight pouches
3. BCD dump valves
4. Suit direct feed.
5. BCD direct feed.
My "closed" mindset meant that I only addressed point 1, 2 and 4.
Also, remember that little hiss I mentioned at the start of this, well when Stewart opened up the direct feed inflator button it was a mass of green gunge and verdigris. So, if you discover a little niggle with your kit, it might merit more than twist, twist squirt!
I was very lucky last night, if I had encountered the same problem on the thirty and forty metre dives that I was doing last week the outcome would have been very different.
That's me then, I just wanted to share this incident with you to raise awareness of how being trapped in a certain way of thinking can have serious safety implications.
Gerry.
Originally posted on CUSAC.org safety forum