Buoyancy Control?

scottmcr1999 Posted on May 7 2004, 07:42 PM
 

(mischievous @ May 7 2004, 05:33 PM)
i will only date divemasters or higher from here on out! 

Dang...

chinacat46 Posted on May 7 2004, 07:35 PM
  I knew there was a reason I needed to get my DM cert. 

Just gives you guys goals to strive for!! :anna:

It hasn't been that long since "buoyancy" was a challenge for me, too; now, my main buoyancy challenge is spelling the word correctly. {I copied your spelling; hope you were right.} Buoyancy and Ear-clearing are the most common newbie problems. I've been forutnate to never having equalizing problems. But I think we all started there with the buoyancy thing (still hard to type right), so don't feel like you're alone - not at all.

I might hold off on the taping thing, though. That'd be too much worry this early, maybe. Get out and dive under safe conditions, practice everything else already offered here, move on to AOW classes with Peak Buoyancy included, then maybe get yourself taped.

For now, though, you're new. You haven't given yourself a chance yet. Another 100 dives and you'll have to think to remember those problems.

Another thought.
If you're renting equipment right now, differences in BCs and suits may affect your buoyancy. Once you get your own equipment, you'll find it easier to adjust automatically. I'm not suggesting you run out and buy all your own stuff right now, just be aware that using different styles of equipment may impact your buoyancy management.

Diverlady

How could I miss this one?

Hey, do DiveCon's count, ladies?

Seriously, as most of the issues that see were very ably discussed, I will add just one more.

When you breathe (and this affects weighting as well, it is a great way to drop weight from the belt), breathe as deeply as you can and then exhale as completely as you can so you have a consistant change with you lung volume. With experience in diving, you will relax and breathe more efficiently anyways. But that sometimes takes concentration.

Just remember, deep breathing is good, shallow breathing is not so good! Hmmmm!

It hasn't been that long since "buoyancy" was a challenge for me, too; now, my main buoyancy challenge is spelling the word correctly. {I copied your spelling; hope you were right.} Buoyancy and Ear-clearing are the most common newbie problems. I've been forutnate to never having equalizing problems. But I think we all started there with the buoyancy thing (still hard to type right), so don't feel like you're alone - not at all.

I might hold off on the taping thing, though. That'd be too much worry this early, maybe. Get out and dive under safe conditions, practice everything else already offered here, move on to AOW classes with Peak Buoyancy included, then maybe get yourself taped.

For now, though, you're new. You haven't given yourself a chance yet. Another 100 dives and you'll have to think to remember those problems.

dont worry Don I could write it a hundred times and still wonder if it was right..

If you can find someone to video tape you that would provide some real insight as well.

JD

Oh geez... I know of a videotape out there that should find it's way into the fire!!! I know you know what I mean, Andrew.

Seriously everyone, Andrew and I have both been through the same class, where they videotape the dives and critique at the end of the day. You would be amazed at how differently you look vs. how you felt you looked during the dives. Then the next day, you really can feel the difference between good and bad. Videotaping really is a fantastic idea for classes.

Diving with an experianced buddy who knows what he's looking for, and willing to give you feedback and advice, will do a lot to help you out.

see jonathan...you just confuse us by going by your middle name (andrewJD) as your screen. i'm not the only one! maybe CT and i can bemoan our mistake over some paint and superglue while we get our costumes ready for regional sd.com dives.

Well, I agree with most of what has been said.

It will definately help to have your own kit. That way you are not struggling to relearn and gain comfort in a new BCD each time.

I do not agree with the position that training should be left for later. It is much better to master the skills the first time and up front than allow yourself to develop bad habits that have to be relearned later when you go to fix it. It is always more difficult to relearn an old skill that you mastered badly rather than just mastering it the correct way from the beginning.

The PPB course can be an excellent and one of the most valuable courses out there if run the correct way. You have to look for an instructor that is really going to build up the course for you and use things like video analysis to help you. Video taping is a hugely valuable tool, especially for buoyancy control work. It allows you to see what you were feeling.

Buoyancy control is the defining skill in scuba. So, it is worth your concern and question on it.

I think that everyone in diving could benefit from working on buoyancy. Few are as good as they believe they are.

You want to shoot for a flat level position in the water as you swim and if hovering motionless. This will take adjusting weights, equipment, swim techniques and breathing. This is what I call working postion. You will want to master several different kicking techniques to have on demand for different environmental needs. Also, work on hovering in different positions and adjusting position with breath control and fins only.

Stop using your hands to do any kind of moment underwater, if you were.

Find an instructor that is willing to work with you in the pool or very shallow water. This is something that should be done in every open water class out there, but unfortunately because of the value instructors get out of teaching open water they simply rarely if ever spend the needed time on this. Work in four feet of water. Swim in this shallow area until you can swim in a good level position without using your hands to position or turn, without contacting the surface or the bottom. Three feet of water is even better. Work on doing this breathing in different ways. Work on it with different kick styles. Make sure you have an good instructor to help with learning good technique from the beginning.

Once you feel you have got it, take your mask off and do it all again with your eyes closed. Sometimes this actually makes it easier for people. Keep working in the shallow end till you can do all this and some other activities while staying level and not touching the bottom or the surface. It is much harder than you can imagine.

Once you have mastered this, you will be much better at buoyancy control. Then, move and repeat the process in different levels of the deep end. Work on hovering motionless in different positons and add doing things while you do that.

Buoyancy does take at least a good thirty hours of diving to really become second nature. You can excellerate the process by doing work like this. The goal is to have nothing happen on a dive with you that is not controlled or conscious. There are no mistakes. It is not the easiest way to go about learning to dive, but once mastered it will make you better much faster. It will free you up to concentrate on just enjoying the dive and being able to do things while diving rather than managing the dive itself.

Breathing is critical. It is the real control. Deep slow breathing is a good start at the basic concept, but does not illustrate the full complexity of breathing well for scuba. I would suggest taking a good freediving clinic if you want to work on breathing. They only have one breath to do what they need to do, so you know the ones they use before they hold their breath are going to be good ones.

http://www.performancefreediving.com/ is a great course to take. One of the best experiences I have ever had. Physiology and awareness of hydrodynamics will also translate to your scuba diving.

Anyway, I like to say you want to imagine that you are filling you lungs from the bottom and emptying them from the top. It is important to understand that 70% of your gas exchange occurs in the lower one third of your lungs. Most people breath out of the top of their lungs. Even while scuba diving, very few really pull gas into the depths of their lungs.

You want to initiate your breathing with your diaphram. Let it drop down and stick out alot. Not the sexiest thing, but really good for breathing well. This can take some practice to master. Once your lungs are half full you add your chest to the inhaltion. Once at a comfortable full breath, pause for two seconds. This is a relaxed pause, not holding your breath. If depth were to change your airway would open and relieve any increase in pressure.

Then, slowly exhale from the top of the lungs through pursed lips or a tongue on the roof of your mouth or restriction of your soft pallate. The idea is to keep the volume up in your lower lungs for the longest time possible. The exhalation will take some time. When done well, you will not need to breath more than four to six times a minute even under heavy exercision. It is the optimum way to breath for scuba. The average experienced diver that masters this gains 20 to 40% increase in gas duration compared to before.

This whole area is what I call breathing parameter. Once you have mastered the ideal breathing parameter, you can change it up depending on your needs. If you wanted to rise in the water column you would exhale even slow than usual. If you wanted to fall you would exhale faster than usual. This can be adjusted further by changing the pace on your inhalation. If you want to stay motionless at a hover you would maintain a more neutral lung voume at all times by not fully exhaling or inhaling.

Breathing is key once you know where neutral is at. You can use the breathing control to help with problems before they are problems. If you are getting buoyant and you are not quick to your deflator, give a good big full exhale to stop or slow the ascent to give you the added time to get the gas out of the BCD. If you see yourself about to crash into the bottom give a quick big breath and slowly release it to allow you to slow or stop your descent into the bottom and have time to adjust your bcd.

The goal behind all of this is to be able to move near the bottom with minimal impact on the bottom or yourself while having the confidence that you know you are in control at all times. The cool thing is that if you spend the time early in your diving career to master this, it all becomes automatic. Then, you do not really have to think about it much.

Ideally, you are adding gas to the BCD on the way down and only touching it to let out the gas as it expands as you make your way back up. All the other adjustments are done with breathing as was mentioned in earlier posts. Rememeber that adjustments take time to take effect.

We all start this process as unconscious incompetents (we don't what we do not know), we evolve to conscious incompetents (hopefully, knowing that we do not know) to finally work toward becoming a unconscious competents (Not having to think about it and being able to do it automatically). The important thing is that we arrive at UC doing the correct things unconsciously. The curve to relearn once you are at that level is painful and long.

Hope that helps. Sorry for the long post.

Grant

Grant,

Absolutely no need to apologize for your long post. It was well thought out and conveyed a great deal of excellent information. It's great to have you on board. You are an asset.

Walter

WOW!!!! I'm officially handing you the coveted "Seajay award for longest post" because you just topped my longest by at least 7 paragraphs, Grant. I can see you'll be a welcome addition to the serious side of SD.com.

That's a lot of good info to absorb, I'm sure you just helped a few people out. I do still disagree with you about getting into a PPB class or AOW class right after OW certification, but I should qualify that by saying it wouldn't be a bad idea at all if there were more excellent instructors out there. I like to question instructors about their teaching methods whenever I meet new ones, and most of them advocate being vertical in the water, using your hands, holding onto the anchor line to control your (vertical ) ascent, and a host of other silly ideas. I don't see how rushing into a PPB class with an instructor like that is really going to benefit a new diver at all. In fact, it's going to do more to reinforce bad habits than it will to instill good ones. I believe that if a diver knows what to shoot for in terms of proper form ( I agree with your description of proper form entirely, by the way ), and has helpful, patient, buddies willing to work with them and provide them with both a good example to follow and constructive criticism after the dive, then time spent in the water with the buddies will benefit them immensely. If they move on immediately into an AOW class, they're less likely to practice the basic skills they learned in OW like reg recovery and replacement, mask clearing, and of course, buoyancy skills in shallower water. Instead, they're moving into new areas like deep diving where the consequences of not mastering buoyancy earlier and being able to stop in 15 feet of water for a safety stop are compounded with additional nitrogen loading. Deep dives are not the ideal scenario to be learning buoyancy skills, IMHO. I'm of the opinion that you should get at least 25 dives post OW certification getting comfortable with the basic skills in water less than 60 feet before jumping into the AOW program and getting a taste for all the cool new situations like diving deeper, diving at night, etc.

Something else that you brought up that's definately worth discussion is your concept of working position. There's a lot of focus on buoyancy control out there in the dive training world, and not nearly as much focus on trim. You really do want to maintain a horizontal position in the water at all times. This will take some time to master and you'll have to play around with not just "how much weight do I need to get neutral" but with "where do I position my weight to be properly trimmed". Most divers wear far too much of their weight around their waist which tends to keep them leg down in the water ( picture their bodies at a 45 degree angle ). Maintaining this kind of trim, they are far less streamlined, and must use more calories and air to push themselves through the water, and it tends to direct the thrust from their kicks directly at the bottom, tearing up the visibility and the homes of many tiny critters. Then they tend to go heads up to ascend and descend, which does very little to control a runaway ascent/descent. Being horizontal and somewhat flared out like a skydiver will present the most drag in the water during the time you actually want drag to slow you down. You shouldn't need to kick at all to ascend, breath control is all you really need to start a slow ascent, and dumping air from your BC ( and drysuit if you're up north ) before you start rising too fast is all you need to manage a slow, safe, ascent.

Excellent post, Grant. It's good to see such an experianced salt in here lending us some of your insight. Keep it up!

.....l just dated a divemaster!

Hmmm. Maybe I should do that?! :anna:

did l mention l was a divemaster?

maybe CT and i can bemoan our mistake over some paint and superglue while we get our costumes ready for regional sd.com dives.

With all those paint and superglue fumes, we won't be bemoaning anything Chie, we'll be laughing ourselves into a vapour induced coma!

Just remember to work with the windows open, okay?

You guys rock! Thanks for all the advice.

Erin,

We're not reading Grant's post the same way.

I do not agree with the position that training should be left for later. It is much better to master the skills the first time and up front than allow yourself to develop bad habits that have to be relearned later when you go to fix it.

I read this as teaching the OW course properly.

When I see:

The PPB course can be an excellent and one of the most valuable courses out there if run the correct way. You have to look for an instructor that is really going to build up the course for you and use things like video analysis to help you.

I take it to mean you don't use the same instructor who screwed up your OW course, but find a good one this time (yes, they are rare). I also take it to mean a well designed PPB class can fix errors in early training. Yes, it's better to learn it correctly the in OW, but unfortunately, most didn't have adequate instruction in OW. PPB (with a different instructor) is for them.

I agree with you on trim, but I think you are relying too heavily on weight positioning to achieve proper trim. Your description,

Most divers wear far too much of their weight around their waist which tends to keep them leg down in the water ( picture their bodies at a 45 degree angle ).

will describe anyone who is negatively buoyant regardless of weight placement.

Anyone who is neutrally buoyant can achieve proper trim. If we were inanimate objects, weight placement would be crucial.

Walter

Walter,

Granted.

But when we are hovering motionless in the water, we are inanimant objects ( tidal lung volume changes aside ) and the placement of weights does play into the equation to a great degree. As bodies in motion, it still plays a factor in the amount of energy required to overcome the degree of angle we assume when not in motion. BC manufacturers allow for proper weight distribution by designing nice little trim pockets higher up on the BC, and since you know I'm a big fan of backplates, I can't tell you how helpfull moving 6# off my belt and onto my back has been in realizing good trim.

Granted.

A lot of us don't get the ideal training the first time out. The internet is rife with debates pro and con concerning agencies, instructors and the like. Some folks live in major metropolitan areas near the coast, and have the luxury of shopping around for different, hopefully better, instructors. I don't. Many of the folks around here don't either. They have access to 1 shop locally, maybe two at best? I don't know if you instruct professionally, but you certainly sound like you have in the past, and you seem very eager to share your knowledge with others on an informal, buddy basis, as am I. I stand by my argument of getting in the water with experianced buddies, ie those like you and me, rather than rushing into the card collecting scenario that most dive shops encourage regardless of the quality of instruction provided through the shop.

A freshly certified diver often won't recognize the deficiencies in their instruction, and will tend to trust the advice of their instructor/shop. Gaining some time in the water with buddies like you and me might give them a broader perspective, and more of an opportunity to discover for themselves whether the level of their initial training was a good value or not, and might save them from continuing with the instructor that wasn't good to begin with, and will help them form solid opinions on what good value in training actually is. This forms the basis of my arguement in favor of time outside of the training loop, rather than charging full steam ahead down the put another dollar in training path.

I completely advocate good solid training with an excellent instructor, don't get me wrong. I'm merely offering my advice based on my own real world observations of what works and what doesn't. I certainly won't stop anyone from spending money on a class, if they feel that's right for them. I just happen to feel 25 dives after OW will help new divers gain a bit more insight into what constitutes a good training path in the first place, and what kind of scenarios they'll encounter outside of the insulated class experiance, hence what they should be demanding from their instruction.

Caveat Emptor is hard to live by if you don't know what you should be looking for in the first place.