Buoyancy Issues

[MikeFerrara]

Originally Posted by MikeFerrara
The bc has been around for a long time. We don't have to sink to the bottom everytime we stop anymore. Don't you think it's about time we really integrate the BC and it's use in controling buoyancy and trim into training rather than tacking a 30 second hover on to the end of the class like an afterthought?

diving started with divers plasters to the bottom of the sea floor..

i was going to say some more stuff.. but in the end.. i have no interest in bantering with such a disjointed member of the dive community.. if you dont like it.. change it..

Don't confuse the "dive community" with the "dive industry". The dive community is all those with an interest in diving. The "dive industry" are all those with a product for sale to the dive community. The buyer beware rule applies.

 

[MikeFerrara]

I think the biggest problem we have Mike, is half the instructors out there can't do this stuff.
The PADI ppb video has dangling gauges and large consoles (which is lol)
The PADI ow has all skills performed on the bottom of the pool
(I'm padi trained I dont know other agencies materials)

Well, yes. Divers tend to dive as they are taught and instructors tend to teach as they were taught to teach. Sometimes it takes a real jolt of some kind for them to realize that the way they were taught isn't the only way or even the best way.

But i'm thankful that PADI got me introduced to scuba, for a nominal fee, whereas a more expensive course would (probably) of kept me away.

My first formal dive training was a PADI class. It was fast, convenient and not very expensive but I think I paid the price later. A lot of the money I spent taking all those classes could have been better spent and quit a bit of it could have stayed in my pocket. I could also have avoided some incidents that had the potential to be real disasters. Better isn't always more expensive, especially in the long run.

 

[scubacoots3]

Time and learning to relax with prober weighting.

 

[Peter Guy]

MikeF -- I think I'm the only person who "suggested" the use of ankle weights -- but I believe you have to look at that suggestion in the context in which it was given. That is, IF someone MUST do a fin pivot then having "heavy feet" (such as you get when using Jet Fins as opposed to Splits) makes it much easier to keep your feet on the bottom -- SO YOU CAN GET whatever benefit the exercise provides.

I am NOT an instructor and have no desire to be one.

I was, however, trying to give the original poster some tips that would help him as opposed to all those who are (rightly) complaining about what a waste it is to even learn that "skill."

 

[Mike Harmon]

OK, folks - an update!

I've done a lot of reading and research since my disappointing confined water session last month. Since then, I've discovered some interesting factoids:

1. There is no such thing as a 9 pound weight (at least not around here). What the instructor gave me was two SIX pound weights, NOT two NINE pound weights (I read the numbers upside down). Thus 12 pounds to start.

2. I was wearing a 3mm shorty, a Glide Plus BCD, and an aluminum 80 CF tank. I'm 6'2" and weigh 280.

3. After I floated all over the place, the instructor hung two 2-pound shot bags on my BCD. Now I had 16 lbs. When I checked weight, I was floating at eye level with a full tank, an empty BCD, and full lungs - I have very large lungs, or at least I've been told so by X-ray techs who had to use a wider-angle shot on me! The instructor added NO MORE weight beyond the two dangle-bags. Total = 16 lbs.

4. On the bottom (10' pool depth and empty BCD), I could lie flat on the bottom only by completely exhaling all the air from my lungs. As soon as I inhaled even a little, or barely touched the BCD inflator, I floated up off the bottom. I could hover (barely) using breath control, but I was "porpoising" - floating up each time I inhaled and sinking each time I exhaled. I told my tale of woe to another instructor at a different dive shop, and he said he thought I just didn't have quite enough weight on.

My original instructor has invited me to join his March class in the pool in a couple of weeks so I can work some more on my buoyancy. I intend to tell him I think I need more weight than I had last time. Maybe 18 - 20 pounds and then go from there.

What do you experts think?

Please don't flame me for my suggestions or questions. I understand that many of you feel that fin pivots are a useless waste of pool time. Likewise others are very sensitive about the issue of overweighting green students. My take on this whole issue is that like it or not, PADI expects me to be able to do fin pivots and hovers. I realize that buoyancy in 30' of water is much different from a 10' pool, but I'm willing to do whatever is necessary to satisfy the requirements and successfully pass the course.

Once I get to Puerto Rico in April and get ready for my O/W check-out dives, I intend to be honest with the O/W instructor, tell him the skills I feel that I need the most work on, and let him exercise his professional judgment as to how to proceed in order to help me be the most successful at the required skills.

If you have any comments or suggestions, I would like to hear them, but I can't change the PADI training guidelines, so please don't suggest that the real problem is something I can't change. All I really want right now is to be able to dive safely and earn my C-Card!

Thanks,
Mike

 

[PerroneFord]

Put on 5 pounds, finish the class and get the c-card. Best of luck and welcome to diving!

 

[loosebits]

Mike, you are going to ascend and descend with every breath. No amount of lead is going to stop or even slow it enough you'd notice (the inertia of extra lead will slow the ups and downs but I'm guessing it would take another 50# before you'd notice).

From in-my-head calcs, a normal adult male adds 14# of buoyancy on a extremely full breath.

Anyway, I never cared for this 500 psi, full breath, whatever method of weighting. It is too unnatural. Let's just say with a near empty tank while breathing normally, you should be able to hang out at shallow depths with little or no air in your BC.

I have no idea how much lead you'd need but if the situation really is as you describe it where the only way you can be negative is to completely exhale then yes, I'd say you'd need maybe another 2 - 6# depending on how much air you had in your tank when you did this test. A very common mistake however is to neglect dumping all the air from your BC because of your position in the water (I've seen people completely feet up trying to dump from their inflator hose).

Now remember, learning buoyancy control is going to be much harder at 10' than it is at 30'.

 

[divedownunder]

When I did fin pivot, I started with no air in my bcd at all... sometimes you have to drop the opposite shoulder to get it all out so you are negatively bouyant.
lying on the bottom face down i took a deep breath and put a couple of bursts in my bcd... if i didnt start lifting off the bottom ... i breathed out and in again adding more air to bcd in 2 short bursts..... as soon as you start raising up you know you wont need much more air in bcd to be neutrally buoyant.

As for floundering around, I did that too abit @ the start, getting comfortable underwater on the bottom took some time, ... i found standing on one leg leaning slightly forward with one foot back behind me was alot more comfy than kneeling

just an idea

Cheers Rich

 

[LIVES4SHARKS]

As a NEWBIE OW with 12 freshwater dives, I will say this. My class did not teach me anything about breathing, (well besides just keep breathing and don't hold your breath) buoyancy, trim, or fin pivots. I was told that would come after about 30 dives. Ok, so not being able to hold myself in the water on dive one will somehow magically change because of some magic number? Thank goodness I was saved from myself by a skilled diver who saw my potential. In one weekend, I was taught and understood the concept of trim. By the 2nd day, I had accomplished a fleeting moment of neutral buoyancy! Now, taking what I had learned, I went to the pool...along with some changes in my set up. Granted, In that weekend, it took almost 20lbs to get me under the water. (hood, 2 part ws total of 6ml) I worked on my breathing in the pool, worked on holding myself in trim, and worked on my frog kick. Now this past weekend, I dropped down 10lbs in the same gear. I also added JET FINS which after getting used to them, actually made it easier to move in the water. Because I had learned to exhale completely on descent, I didn't need all the weight to get me under. However, ascending will take alot more work. I do have much more control with my descent and no longer bounce off the bottom. The amazing thing I found, when moving in the water horizontal, hands clasped in front of me, the fish swam with me. They also were very friendly when I hovered. When you aren't stirring things up flailing around, they tend to want to check you out! So. as a new diver coming into this sport, I found the OW course through SSI to be very lacking, and when it came to safety, the thinking was it probably will never happen. Umm, I do not think that way. Call me a pessimist, but I prepare for the worst, if it doesn't happen then it has been a good day. I am headed back to the pool one more time before my trip next week to the Bahamas. It will be my first Ocean dive so I am a bit anxious. I am going with my instructor and others from my dive shop. I know they will be looking out for me, but I am grateful and lucky that I have had alot more training outside my LDS to get me where I am now. Practice, get comfortable, and learn from other divers. That is what has been working for me!

KUDOS to my MENTOR and DIVE BUDDY PERRONE FORD! Without him, I would still be flailing in the water scaring all the fish and probably the other divers!

--Carolyn

ONWARD, DOWNWARD, and into the BLUE!

 

[LIVES4SHARKS]

"i found standing on one leg leaning slightly forward with one foot back behind me was alot more comfy than kneeling"

I hate kneeling, it gave me cramps! Plus, who wants to kneel when you can hover? LOL!

--Carolyn