Buoyancy Issues

[PerroneFord]

fin pivots are a lead in to hovering.. both skills are essential to learning how to control your buoyancy.. whilst diving i rarely do fin pivots (out side of demonstrations) however i consider my buoyancy control to be exemplary and i understand the reasons fin pivots are taught.. with out it to tell a new OW diver to hover would lead to many frustrated divers.. usually it takes up to 30-40 dives before most divers are comfortable with thier buoyancy.

*flame suit on*

I have taught several divers to hover. And none by using the utterly wasteful fin pivot. I have then lay on the bottom of the pool, in proper trim position and breathe in to try to raise off the bottom. If they cannot, they add 2 bursts in their BC, and repeat. I do this in 4ft of water. I have taken divers from being unable to gain neutral buoyancy, to netural, trimmed, and working on frogkicks in 2, 3 hour sessions.

To the original poster: If I am properly weighted on a dive, it is nearly impossible for me to kneel on the pool bottom. Those who can do it easily are overweighted. Do not take their being able to perform this as some "positive" thing. Learning to be neutral in a shallow pool, is very, very hard. And it's why I work with new divers in the 4ft section of the pool, before moving to the 10ft section. If we can get them neutral and swimming in 4ft, they'll be comfortable everywhere else they dive.

I truly wish dive instruction would get away from the idea that "kneeling on the bottom" to teach is a good idea. It's a crappy idea. And when I help with classes, we establish neutral buoyancy and then the lessons begin. Brand new diving students, neutral in 4ft of water, lesson 1. You do not have to kneel on the bottom to teach diving.

To the person who says you don't hover when diving, I find the only people who don't hover, are people who cannot hover. I hover on every dive in the water. To bubble check, to look at my SPG, to enjoy the wildlife, to practice OOAs, to write something in my notebook, for my safety or decompression stops, to shoot a bag, to assist my buddy, or to simply enjoy being weightless in the water.

 

[TSandM]

Perrone, as won't surprise you, I agree wholeheartedly, especially about hovering. One of the most utterly wonderful things I can do underwater is nothing. It took a lot of work to get to where I can hang absolutely motionless, and it's exhilarating.

 

[MatWill]

I have taught several divers to hover. And none by using the utterly wasteful fin pivot. I have then lay on the bottom of the pool, in proper trim position and breathe in to try to raise off the bottom. If they cannot, they add 2 bursts in their BC, and repeat. I do this in 4ft of water. I have taken divers from being unable to gain neutral buoyancy, to netural, trimmed, and working on frogkicks in 2, 3 hour sessions.

the thing is.. what is proper trim position... hovering is totally different to fin pivoting and hovering horizontally is a different skill to hovering upright

and i can guarantee you that 90% of new OW divers will be over weighted for there first few dives (if they are not i will make sure they are) this is to make sure they can kneel on the bottom so they can do there basic u/w skills.

its one thing to say to a new diver.. just weight yourself properly.. or attain proper trim please..

its totally another to actually show them what your talking about and have them understand what your saying.. i would guess the total amount of new OW divers that get trim and buoyancy correct during there first OW course would be around 10-20% in my experience... as long as they understand what they are trying to attain then they are 99% the way to getting proper buoyancy in there diving.

 

[TSandM]

and i can guarantee you that 90% of new OW divers will be over weighted for there first few dives (if they are not i will make sure they are) this is to make sure they can kneel on the bottom so they can do there basic u/w skills.

.. i would guess the total amount of new OW divers that get trim and buoyancy correct during there first OW course would be around 10-20% in my experience...

I'm going to don my flame suit and suggest that the two quotations above are related.

If buoyancy control is one of the central skills of scuba diving, and the OW class is supposed to teach one to do elementary diving safely, is it acceptable if only 10 to 20 percent of the students have a basic grasp of this skill at the end of the class? If not, would it not be reasonable to look at WHY students don't come out of OW with a grasp of this skill? Is it possible that teaching students to kneel, overweighted, on the bottom of the pool does not even begin to give them a feeling for either good diving posture OR the experience of neutral buoyancy? Or that fin pivots are not the best way to convey breath control of buoyancy?

Perrone has described how he teaches buoyancy. Snowbear posted pictures a year or so ago of a brand new OW class, showing lovely positioning and horizontal trim. I know there are other instructors on SB who have adopted some different approaches to teaching buoyancy control, and are reporting significant success.

Rather than vociferously advertise a teaching technique that is only 10 to 20 percent successful, would it not be better to consider how the teaching could be revised to work better?

 

[PerroneFord]

the thing is.. what is proper trim position... hovering is totally different to fin pivoting and hovering horizontally is a different skill to hovering upright

I can say without question, that at no time, on any dive, did I ever have a need to hover upright. When do you find this skill helpful?

 

[fisherdvm]

My wife and I completed our pool dives last week. Most of the skills were no problem - mask flooding/clearing, sharing air, regulator/snorkel exchanges were a piece of cake. Our weight was perfect - eye level floats, etc. However, both of us seemed to have a lot of trouble with buoyancy. It seemed every time we took a breath, we headed for the surface! Attempting to do fin pivots was very frustrating. I could lie on the bottom of the pool, and inhale a little, and before I could exhale, I had already floated completely off the bottom. It didn't help that we and one other guy were the only adults in the class who had never been underwater before. The rest of the group was doing refreshers. Talk about sticking out like sore thumbs! Most of the people in the session could kneel on the bottom of the pool with no problems whatsoever, but it seemed like we were floundering about like beached whales!

Most of the people I've talked to since have tried to encourage me by saying that everyone has trouble with buoyancy until they have a few dives under their belt. However, we are planning to do our open water certification dives as a referral in Puerto Rico in April while we are on vacation. We don't want to be the only ones in the OW class who can't seem to stay in one place for longer than a few seconds at a time. As a matter of fact, I've asked our instructor to let us do the pool dives again just to see if we can do a little better the second time around. He says he doesn't worry about our safety and is comfortable with referring us for our OW dives, but I just don't have the self-confidence I thought I'd have.

What do some of you old-timers think about our concerns?

Thanks,
Mike

If you check for neutral bouyancy at the surface with a full tank, you will need to add extra weight to compensate for the added bouyancy when your tank is empty. Most tank loses about 5 to 10 lbs of bouyancy as they become empty, so if it is toward the end of your pool session, you might find it very difficult to keep on the bottom. I would add about 6 to 8 lbs of lead the next time you do your bouayncy check with a full tank.

 

[spectrum]

The eye level float method of weight checking (which is a good) needs to be done with a near empty cylinder to get it right. In your cases you must have done it at the onset of the class and would need to add an additional 5-6 pounds of weight.

You probably had 80 CF cylinders. Lets say you intended to consume 70 CF of air. Air weighs .08 pounds per CF. 70 X 08 = 5.6 pounds of weight you will loose during the dive. You can see that before long you will be getting downright buoyant without that extra 5-6 pounds.

It's always best to repeat the test at the end of the dive (or pool session) since early in the dive you can have a pound or 2 of stowaway buoyancy in the form of air trapped in padding, fabrics and such. In any event you are much safer diving a pound or 2 heavy that being a little light.

Not too many things are as frustrating as being under weighted and to be so while cutting your teeth must have been a pain. While it would have been nice if your instructor had caught on and helped you have a more productive session at least he (she) did not blindly overweight you two.

Let this be just a tiny lesson. When things go bad on a dive it's usually a combination of things. You can imagine for instance that if you had to help your wife adjust a piece of gear at depth both being under weighted would have exacerbated the task. Take charge, proper configuration is a huge part of good diving. I fully appreciate that in that pool session life was a blur and you wanted to stay on task to maximize your bubble time.

As for your concerns (I'm not necessarily accepting the old timer moniker) they are well founded from a "lack of proof" perspective. From all you write you and your wife did fine on the actual dive skills. As you mention buoyancy control takes a while to develop and I found it really hard to be really decent when I was really new and in a pool. There is just too much going on and it seems like I was always taking evasive action for someones else's fins or arms! In all likelihood you will do just fine when properly weighted. Be sure that you get to do the weight check to your satisfaction before the actual dives. Remember that gear for gear you should need 6 pounds or so of additional weight to offset the higher density of salt water.

But let's get real here. There are about 2 months between now and your vacation and you don't need this crap hanging over your heads. Tell your instructor that you and your wife really want to get back in the water to get this right. Letting students jump in with a subsequent class (NC) is SOP. My wife got off to a slow start and we went back a few weeks after for a few evenings and it was great. We did all of our drills on our own and cemented our skills as a buddy pair, at least as much as you can do at that point!

You paid for the training and you have a vacation investment as well. I honestly think that your instructor was right about you being ready but if your plan is to get certified and dive your hearts our for the balance of your stay in Puerto Rico bag every minute of pool time you can!

As an aside... If you are really going to dive right into this let me suggest something else.... Between now and the vacation get into a public pool a few times a week with your mask, snorkel and fins and run some laps. Nothing will do a better job of toning your legs to make them cramp proof. Even with gentle diving the sudden leverage of fins can give your muscles fits. Also it's a cheap and simple way to really get accustomed to sustained deep controlled oral breathing and having a wet face. When you cross the 75 foot pool at a moderate speed on 10-12 breaths you are in the ballpark. After 20-30 minutes cool down with some skin-diving practice.

Have a great time competing your certification and on the vacation. Remember... we all expect to hear a full report.

Pete

 

[fisherdvm]

A tip to keeping you down on the bottom on a real dive as you start to float to the surface at the end of the dive is to find a rock big enough to keep you down. Hang on to it with one hand, or stuff a couple in your BC. This will let you stay down and not bubble to the surface where hazards can await you.

Many DM carries extra weight, you can gently tap them and request a few pounds for your BC pocket.

 

[RJP]

If you instructor says you're fine, despite the fact you have major buoyancy issues, i'd suggest you get a new instructor.

"in my opinion fin pivots and mid water hover are a cpl of the best skills to master as a new diver as they will carry you through the rest of your diving life"
This is bollox , how will 'fin pivots' carry you through any diving, are you regularly doing pivots on coral reefs or something????????

A.) I think the OP is MUCH better off with the instructor that he has - all other things considered equal - compared to the majority of numb-nutz instructors that espouse the "overweight yourself in the beginning" philosophy. Most instructors I see running classes blindly hand everyone 20lbs of lead and look more like they are runninng "Discover Silting" or "Intro To Reef Destruction" than OW.

B.) Fin pivots and midwater hover are the ONLY skills of the "20 skills" in the standard curriculum that really and specifically teach bouyancy control. Done properly they will give a diver a true appreciation for just how easy it is to fine tune bouyancy.

I think the problem with fin pivots and neutral hover is that they are taught as "necessary skills" as opposed to "useful demonstrations." As PerroneFord suggests, the best thing to do is to actually teach "bouyancy control" and get students neutral before moving on. The problem with that approach is that it IS hard, and can be very frustrating and demotivating to newbies. There's a way to split the difference.

My instructor made sure I had neutral bouyancy and trim pretty much mastered by the end of the pool sessions, and was less concerned that I had them nailed down by the end of confined water dive 1. I know for ME that was the best approach because I had a real problem early on with fin pivots and hovering. If I was called upon to master these before moving on to other skills I may have given up!

 

[MatWill]

I can say without question, that at no time, on any dive, did I ever have a need to hover upright. When do you find this skill helpful?

actually i rememeber alot of tours with newer divers where i helped them underwater with there buoyancy or trim in the upright position..


i dont really want to argue with anyone.. the best thing is to understand what your doing.. and the rest will follow...