surface descent

[subaquaman]

Ditto what's already been said. It sounds like your doing the right thing and many not need to add any more weight. Two techniques you might try.

1. Try exhale for 12 seconds. It's pretty much the opposite to what Andy said, but I'm only putting it out after seeing it work first hand. By the time you go to inhale you should be sufficiently under the surface to have the neoprene begin to collapse.

2. Try a pendulum movement. After dumping ALL the air from your BC, fin as hard as you can, trying to get your body as high out of the water as possible, then exhale and stop finning. Your height then helps you crash back through that initial few metres before the neoprene collapses and you can continue your descent.

Obviously these methods rarely work in harmony because of the need for an inatke of breath after exercise, but they've both worked for divers I've been with. Let me know if you try them and how it works out!

 

[ScubaDadMiami]

As you are getting ready to descend, you want to lift your arms out of the water to help push you under. You are probably already lifting your left arm out to deflate your wing anyway. So, just add the other arm.

Once you are under, you can turn horizontal and start to kick down. That way, you won't go back to the surface.

Now, if you are saying that you will go to the surface with an empty bladder from ten feet even after descending and doing the dive, then it is time to start looking at adding weight. It sounds to me like you are already pretty heavily weighted now. But, just wanted to bring that aspect up in case.

 

[kazinvan]

Sounds like you need to strap on another 20 pounds or so. Just kidding You seem to have near perfect weight, personally I would add a couple of pounds since if I'm that close to perfect at the start of the dive then I'll be too buoyant at the end and it won't be easy to hold the safety stop. Others may disagree, but I like to be just a bit negative at the start. I'm assuming you are using an AL tank. If steel, they you are at a good weight. Like the others have said, you will learn how to descend with a few more dives using the current weight.

 

[dmmike]

To stop unconsciously finning - cross your feet for descent.

Rob,

This is right on, the only additionial thing I do is I point my toes downward. I'm not sure how this would work with split fins or "normal" fins, I use Force fins.
I've used this method for years and it works great.

 

[m3830431]

I have been waring a farmer jon 6.5 mm hood gloves and boots in Green Bay-Lake Michgan with 26 lbs. of weight. It takes a little push to get to four feet before I can descend easily. No problems at 15 feet with 500psi. I am 6'2" 195 lbs.

 

[lorien]

Lots of good advice here. When I start to descend I empty my BC and exhale fully. Yes, I then need to inhale but I only use a very small inhalation followed by a complete exhale again. It is only the first couple of feet that usually give a problem, once you are below that problem solved.

 

[Ishie]

When I have a slight problem with that sort of thing, though I'm trying to descend in a horizontal position, I get slightly vertical, head-down, keeping my buddy in sight, and just barely move my fins (same sort of motion people do unconciously finning up). This gets me below ten feet and then I can do a slow controlled descent in a horizontal position.

I don't know if this is easier or harder in a vest though. I'm in a BI BC.

 

[pt40fathoms]

OK, I'll be the one to buck the trend in saying "you seem to be perfectly weighted".

If you are doing this "pop up" with a full tank at the start of the dive, and you are NOT kicking like a panicked diver on the surface, you are under weighted!

Your tank will be 4 to 6 pounds positively buoyant and the end of your dive, you need to do a weight check at the END of a dive in order to establish proper buoyancy. Doing it at the start of a dive and guessing is just that, a guess. It may be close, but nothing replaces doing it after your dive is done.

So, add at least 4 pounds, cross your ankles, let the air out of your BCD, exhale to a normal comfortable point, and when the dive is over check your buoyancy and adjust.

When you have a few dozen dives under your belt, and you are more at ease with your gear and diving in general, you may find that you will need less weight. Until that happens, stop struggling and enjoy yourself. Diving should not be work, and it should be fun. If you are trying to "be perfect" right off the start and end up not enjoying yourself, you run the risk of getting frustrated, loosing interest, and taking up stamp collecting as a hobby instead.

 

[Daryl Morse]

OK, I'll be the one to buck the trend in saying "you seem to be perfectly weighted".

If you are doing this "pop up" with a full tank at the start of the dive, and you are NOT kicking like a panicked diver on the surface, you are under weighted!

Your tank will be 4 to 6 pounds positively buoyant and the end of your dive, you need to do a weight check at the END of a dive in order to establish proper buoyancy. Doing it at the start of a dive and guessing is just that, a guess. It may be close, but nothing replaces doing it after your dive is done.

So, add at least 4 pounds, cross your ankles, let the air out of your BCD, exhale to a normal comfortable point, and when the dive is over check your buoyancy and adjust.

When you have a few dozen dives under your belt, and you are more at ease with your gear and diving in general, you may find that you will need less weight. Until that happens, stop struggling and enjoy yourself. Diving should not be work, and it should be fun. If you are trying to "be perfect" right off the start and end up not enjoying yourself, you run the risk of getting frustrated, loosing interest, and taking up stamp collecting as a hobby instead.

I hear yah, man. When you're diving with an AL80, just to be neutral, you should be ~6 lbs negative at the beginning of your dive. When you're 6 lbs negative, if you dump your BCD, you will sink. Inhaling will slow your descent, but you'll still sink. Even finning will slow your descent, but your tendency will still be to sink. The only thing that might keep you from sinking would be air trapped somewhere other than in your BCD and lungs. If you have to utter a secret mantra or assume a yogic descent position in order to sink, you probably are underweighted.

I normally dive dry so I do my best to squeeze the air out of it before I gear up. Even with a bit of residual air in my drysuit, I can still sink without difficulty at the start of my dive. At the end of my dive, I feel a bit floaty upwards of 10 fsw, but I still can linger just below the surface if I choose to. A couple of times on trips, I've noticed a bit of difficulty sinking due to air retention in a lined wetsuit. I get around that problem by thoroughly soaking the inside of my wetsuit with the warm water hose. (It's going to get wet anyway, may as well be warm water.)

Next time you go diving, at the end of your dive, purge your tank down to 500 psi and do a buoyancy check. If you can't keep yourself just below the surface, you are underweighted. It would be great if you could find a way to shed a lb or two at at time until you can't keep yourself from ascending. When you get to that point, you'll know you're at the point of minimum weight. (Personally, I wouldn't consider it to be a capitol offense to have a couple of extra pounds while you're getting adjusted.)

 

[ciret]

Good discussion.

I'm wondering if there is a way to estimate the weight change I would need to make going from warm salt water to cold fresh water? I'm 6' using a 2.5mm shorty AL80 and 12 lbs. If I'm in a 5mm full suit in fresh water what do you think I will need.

Sorry if this is a hijack, I thought it sort of fit. Feel free to split it if needed.

Thanks,