The larger tank, the 100 cf, has a greater buoyancy swing from full to empty than you were accustomed too with the 80s you probably normally use. N
Came up too fast
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Crush
Contributor
I'll add my voice to the chorus.
I am glad that you are OK.
I have seen many divers depress their BC air dump button while the dump is not held higher than they are in the water column. No air flows out. Mystified (and perhaps rising) they hold the dump in front of their faces to look at it (not high enough up, depending upon their attitude in the water) and depress the button again. Again, no joy.
You might consider practicing a recovery from this situation. If you are not in a drysuit, practice inverting yourself and swimming downwards with slow, powerful kicks all the while venting your BC from it bottom dump valve(s).
I am glad that you are OK.
I have seen many divers depress their BC air dump button while the dump is not held higher than they are in the water column. No air flows out. Mystified (and perhaps rising) they hold the dump in front of their faces to look at it (not high enough up, depending upon their attitude in the water) and depress the button again. Again, no joy.
You might consider practicing a recovery from this situation. If you are not in a drysuit, practice inverting yourself and swimming downwards with slow, powerful kicks all the while venting your BC from it bottom dump valve(s).
R
redacted
Guest
Unless the wetsuit was a 5mm, then you were surely overweighted. If the tank was an Al100, then you were probably just somewhat overweighted. If it was a steel tank, then you were grossly overweighted. But overweighting just makes you work more (adding and dumping air from your BCD) to control your buoyancy. Only in the extreme does it cause you to lose buoyancy control and that loss is a trip down, not up. The problem was that you failed to control your buoyancy by dumping air from your BCD when you needed to. Being properly weighted will reduce your work making buoyancy adjustments but it will not keep you from an uncontrolled ascent when you don't make the correct adjustments. Practice, practice, practice.
on_two_wheels
Contributor
I'm going to be one of those that suggest maybe it had nothing to do with weight or equipment. Perhaps you just had a day of poor performance. As a new diver I'd suggest that's more likely than equipment malfunction. At that level of diving, trying to do a safety stop in open water (not holding a line) it's not unreasonable to suddenly be a couple feet too shallow, then suddenly at the surface before you react. Learn from it, drive on.
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Still happens to me at times. Maybe when I hit 500 dives I'll be better? But I am a klutz. :silly:
Blackwood
Contributor
My armchair 4-beers deep opinion is that you were overweighted and allowed the gas in your BC to get away from you.
Going from 80 to 70 without dumping is not a big deal: the buoyancy gain is hardly significant and unless you're very comfortable, still and aware in the water, you won't notice it. However, at 80, there is 50% more ambient pressure than at 40, and thus quite a bit of gas expansion on ascent. Compound that with the fact that you are intending to ascend which likely disguises the constantly increasing buoyancy.
Some suggestions.
1) Do a proper weight check (a few above have described the process) any time you change gear.
2) After your initial descent, when you are neutral at the bottom, reach back and squeeze your BC. That will give you a feel for how much gas you need in it at depth. If you ascend, the wing will feel fuller, which is unfortunate since you're literally exhaling weight AND your wetsuit is expanding, thus meaning you need less and less air in the wing. With time, you should be able to reach back while ascending, feel how full the wing is, and realize "nope, that's too much," and proactively dump before reaching your stop depth and not being able to hold it.
Those two things helped immensely when I was first learning.
Going from 80 to 70 without dumping is not a big deal: the buoyancy gain is hardly significant and unless you're very comfortable, still and aware in the water, you won't notice it. However, at 80, there is 50% more ambient pressure than at 40, and thus quite a bit of gas expansion on ascent. Compound that with the fact that you are intending to ascend which likely disguises the constantly increasing buoyancy.
Some suggestions.
1) Do a proper weight check (a few above have described the process) any time you change gear.
2) After your initial descent, when you are neutral at the bottom, reach back and squeeze your BC. That will give you a feel for how much gas you need in it at depth. If you ascend, the wing will feel fuller, which is unfortunate since you're literally exhaling weight AND your wetsuit is expanding, thus meaning you need less and less air in the wing. With time, you should be able to reach back while ascending, feel how full the wing is, and realize "nope, that's too much," and proactively dump before reaching your stop depth and not being able to hold it.
Those two things helped immensely when I was first learning.
OP
stormchaser
Registered
I will take all yalls advise and learn from it. Practice practice practice is needed. This dive was only my 3rd after my open water training in the quarry. Thanks everyone!
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70 miles. Go dive Athens.
There is deeper diving somewhere east of Dallas, ask on the Texas forum, or if you want to do Santa Rosa NM Blue Hole enough I'll dive with you - and behave! 10 hour drive from there tho.
Guba
Contributor
Clear Springs Scuba Park (east of Dallas) bottoms out at about 60 feet...and that's in a pretty narrow "silo". Possum Kingdom Lake (no, I'm not making up that name) west of the Ft. Worth/Dallas metroplex has plenty of deep dives, but you will need a boat to properly access them. A little bit to the north, there is Lake Murray (near Ardmore, OK) and Lake Elmer Thomas (near Lawton, OK). Both have deep dive opportunities. My buddies and I dive all these places regularly. Drop me a line and we'll be glad to hook up for some dives.
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