Bouyancy Control, Wetsuits and Shallow Water

[1611kjb]

I am new to diving. I just got my Open Water in August. I did all my diving in a quarry and my skin, so I didn't really do any training wearing a wetsuit. I'm in Ohio; Autumn is chilling the air and water, so I now have to wear a wetsuit. I decided on 5mm since I don't get cold easily (I'm big/obese). I figured 7mm would be too thick unless I was going to ice dive and less than 5mm I can probably get by skin. I'm pretty comfortable diving in 75 degree water without protection.

So, here's my problem. The quarry I use is only 20-25 feet deep. Many parts of it are in the 12-15 ft range. It appears that the compressibility of neoprene happens right about that point. If I am above 12', the suit is not compressed at all and I bob to the surface almost without control. I have to exhale everything in my lungs and hold it to start a descent. I wear 12 pounds of lead. Now, I could add weight. However, as I descend below 15', the suit starts to compress. Below 18', I drop like a rock. Anything short of a maximum breath has me sinking. Consequently, I add a little air to the BCD to keep me from walking across the quarry. However, the bottom in some areas undulates. And as I rise to the height of 12', and now I have added some air to the BCD, I start and unplanned and uncontrolled ascent to the surface.

So, here's my question: How do you maintain buoyancy controls when your target environment is right in the range of wetsuit compressibility? I seem to always have too much or too little weight and there seems to be no buoyancy control.

Also, what are some good exercises for buoyancy control? What's the best way to practice? I find control to reflect an analogous situation in flying airplanes (there we call it pilot induced oscillations). That is, the timing for recognition, adjustment and balance is usually over and under corrected frequently and excessively and you end up porpoising up and down instead of maintaining an even depth.

Then there is the problem of maintaining control when swimming versus when holding still. When I hold still to look at something, horizontally, my legs rise. However, they are level while I am swimming. I assume some level of unconscious control keeps me kicking in a pattern that keeps my legs straight. However, I am frequently near the bottom and if I make adjustments with weights to keep my legs down when I stop, when I start kicking again, I silt out the area. How do you keep yourself balanced horizontally when not kicking?

 

[RonzoTheGreat]

GREAT QUESTION and concerns as well ....

there are many aspects to touch upon in your post.

i am NOT a small guy and know what you mean by us having "better insulation" than those damn skinny people, however, i must warn you that as you become more comfortable in the water, your body will become more relaxed and you will use less to accomplish the same or more ..... leading to lowering your overall body temp and becoming cold ... i am also diving in the same latitude as you so know about the temps ... so you may want to consider the 7mm after all ...

over weighting is a common mistake among divers who want to become "more buoyant" as well. glad you sort of recognize this. the truth is, as you descend, no matter who you are, if you are not constantly adding air to your bc (or drysuit) you WILL accelerate as you descend.

not sure what your LDS is like and who your dive agency was, but padi's peak performance buoyancy class CAN BE a big part of the answer to this question. (if yuor LDS is poor, as many are, than the class could also be a waste of time and only a money maker).

it is ALSO common for newer divers to experience buoyancy issues at shallower depths. this will come with time and practice as well.

at the end of EVERY dive that we do from shore, we slowly ascend (normally) venting every few feet, and ANTICIPATING the "popping" that sometimes occurs with newer divers, and we dive all the way to the shore line until our computers can barely read the depth (2-3 feet).

you can make it a sort of contest amongst your buddies as well, to see who can make it to the shallowest part of the entrance without breaking the surface.

are you flutter kicking or frog kicking?

gear can play an important part of your balance in the water. where your weight is placed can effect a head too high or feet too low and vice versa. trim is important ... your body position will also determine your buoancy quite often. some BC's and fins can assist in keepoing your head down and feet up and something as simple as how high or low you place your bc on the tank as well.

silting ... a propper frog kick can really assist with keeping the silt down ...

when you stop as opposed to kicking ... think about your body position while in motion ... just as your hand if you put it outside the car window while driving ... it's like a plane ... but once you stop ... there is less friction and trimming via the medium (air/water) so you may tend to lose the prior position in the water ...

good to hear you are really trying to use your lungs to control your buoyancy and not solely relying on your BC ... you can actually not exhale or inhale all the way rather than filling your "big guy" lungs. i have huge lungs and also experience great difficulty in the beginning when trying to find neutrality. use your fin pivot to find a somewhat neutral position ... than use your breathing once you find it ... add only small amounts of air as you descend (and often if needed) but DONT lay on the inflator. (same goes for ascending and venting)

remember what i mentioned about anticipating ... this is important for everyone, and the more experience divers probably dont even realize they do it anymore.
for those of us in drysuits ... it is VERY important, for those of us in wetsuits, it is only slightly less important. as i move from a summer (no undergarment) to the fall undergarment to the hiloft winter undergarment i find that i need to anticipate the air making its way to my vents a little bit ahead of time or else i may also experience a sudden ascent ... so when i know i am going to be entering a thermo cline or even on a normal ascent ... i actually start venting immediately (small amounts and often) never exceeding 1 foot per second.

my lds has a great peak performance buoyancy class that is actually required for staff members ... you are far west of us so i am by no means suggesting you take it with them, im just pointing out that a class well done is worth every penny as opposed to those who will bash it (due to lack of commitment of their lds).

try going in out and around all of the platforms at your quarry ... try hovering on them at the lowest possible depth in a horizontal position ... try playing poker or 21 with water proof weighted cards without touching down ... these are all things we do often (on every safety stop at minimum) and on most dives.

these ARE my own opinions and experiences, so some may disagree, but i really thought your questions were great and hope more people chime in to assist you with them.

and finally ... the best thing you can do to be a better diver, is dive.

be safe
ron

 

[RonzoTheGreat]

one other thing ... you mentioned several times about the neoprene condensing ... that is not just going to happen at your depths but as you go deeper and deeper it will not only occur more and more leading to a pretty speedy descent, but it will ALSO LOSE thermo characteristics, which is why so many of the northern divers go dry ... (i am not telling you or even suggesting you do this, just sharing some information)

 

[Randy43068]

Hey 161 you're addressing an issue that isn't IMO covered well in OW classes. It's called dynamic instability and gets worse as you wear thicker and thicker wetsuits. Personally, I think a 7MM and thicker is worthless if you want to maintain fine buoyancy control without always working the inflator/dump valves.

It's just a lot of work to dive as your wetsuit gets thicker. I'm sure there will be a slew of "experts" chime in saying they have no problem at all. I say BS, just watch them in the water, and of course your experience illustrates the phenomenon well.

Having said that, please know that the more you dive the easier it will become to control your buoyancy, but wearing the wetsuit you'll always have to be more aware and will require more active input from you to maintain your position in the water.

With a wetsuit you will always be underweight on the surface, and over-weighted underwater. The cause is as you noticed, the crushing of neoprene as you descend and it's expansion as you move up in the water. The same happens to folks wearing a drysuit, but it's not as pronounced which makes fine buoyancy control MUCH easier.

By the way, welcome to Scubaboard.

P.S. Ronzo is giving you good info..

 

[1611kjb]

The problem with picking and LDS is the learned usually lacks sufficient knowledge to know if the problem belongs to the LDS or the student. Mine seems pretty good, but I haven't been able to take the issue up with him through a rather unusual set of circumstances. Rights after getting my OW, he got a gig in the Bahamas for 6 weeks. He was hired by the US Government for this job, so I assume that says something for his credentials. In any event, he's do back in two weeks, so I'll ask him more. I wasn't really planning on doing a lot of diving when I started this. I am not only large, but I seem to have left the largest part of my youth behind me. So I was planning on using this for catharsis and never really going much beyond Ohio and maybe a yearly vacation to some tourist trap in a warm location. However, after I started telling folks I did this, I started finding I know people who dive. I've already been invited to dive this Spring in the Carolinas near Hatteras to see a wreck at 165' and an invitation to dive Lake Tahoe. So, my LDS says I need Advanced Open Water training, Nitrox Training and an Altitude Diving class to pull all that off. We never got to talk about a buoyancy class because I hadn't put on a wetsuit yet. I'll have to mention it to him and see what happens.

I was certified under the YMCA. I've been a water baby all my life and meant to learn to SCUBA for years. An opportunity arose, so I took it. It turns out the YMCA is dropping SCUBA this year and so I will need a different Agency for any training I do. I suppose PADI is as good as any other. My LDS has instructor certs in basically all the organizations and he holds all/most of the cert levels. He teaches other teachers, does wreck, rescue, technical, hazmat, commercial and a bunch of others. Of course having a cert doesn't make you a good instructor, it simply means you were a good student.

Regarding your specifics, I can do all the kicks. For normal propulsion, I use a flutter kick and it's not the kick that is giving me problems. As I said, when I hold still, my legs rise. Literally, if I try to hover while I am messing around with some rock or snails on the bottom, my feet will rise right over my head. The "logical" way to control that would be some ankle weight. If I weight my legs so they are lower, I end up horizontal, or feet down (heading for vertical). From that position, any kick - the type doesn't seem to matter, stirs up the silt. Since there is no buoyancy control in your ankles, weighting there seems to be a bad idea. The alternative to weighting is some sort of leg motion that holds your feet down. Again, a flutter kick will do that, but you can't hold still and kick. So, how do you hold still and keep your ankles down? I'm fine without the wetsuit. I can hover there pretty well, but once that wet suit goes on, my legs are quite buoyant.

 

[1611kjb]

Thanks - glad there's a SCUBA board to discuss issues. I have more, but I'll throw them out one at a time.

Is there a good book, online reading or some information source where I could learn about dynamic instability?

 

[Randy43068]

Thanks - glad there's a SCUBA board to discuss issues. I have more, but I'll throw them out one at a time.

Is there a good book, online reading or some information source where I could learn about dynamic instability?

I'm just up the road from you. Let me know when you wanna dive, maybe I can get away then.

 

[1611kjb]

Super, you gave me the right terminology, "Dynamic Instability". I googled it and found some good info on both Static and Dynamic instability and it appears both are causing me a problem.

From Diving Niknaks - Advice Site - Conger Alley, Scuba Diving In Scotland

Now I can research and experiment - thanks.

 

[Randy43068]

Glad to be of help. Unusual for me.

 

[TravisD]

Use the shallow quarry to your advantage -- my wife/buddy and I have spent many dives simply circling the edge of the quarry, staying in the 10-18 foot range. It has definitely helped us build better buoyancy control. The wall gives you a visual reference for maintaining depth, without having to rely on a hard bottom. As you get more comfortable you can move further away from the wall - sort of take off the training wheels a little at a time.