Buoyancy vs trim vs BCD vs Wing

[o2dependant]

I’m still relatively new to diving. And am relying on rental equipment for the moment. So each time I dive or should I say each set of diving that I do usually requires me to use different equipment.

I have benefitted from it. Had I been in the UK when certified I would have likely bought all my gear before the first class, and by now looking to replace some of it.

I have used a few masks that I really liked and decided on certain items that I felt work well for me. I have had the opportunity to try out a back plate and wing that I felt will be my preferred choice for my setup. And have decided on my fins, Dive computer, torch, SMB style, bought my booties leaving the only thing I really need to work out is what suit and regulator kit( all the regs I have used have been as good as one another)

I have found that my buoyancy during the dive is fine. I can hold a line and get around objects get vertical to look under coral tables etc and feel really comfortable. Some comments made have led me to believe that I’m doing ok for my level of experience. I think its down to my high level of activity and my conscious effort to improve my skills that has benefitted me most.

I have been reading about Trim and my last set of dives I decided to see where I was. So whilst I was waiting for the others to join me and my buddy on the bottom (one was a little light on lead) I got horizontal and held it for a moment. I noticed my legs slowly sinking down and I started to turn belly up. So I shifted my weight belt a bit and got to the point where I was still dropping my feet but no longer turning over.

I guessed I would move a few lbs up onto the tank to try and balance myself out for the next dive. Sticking a weight onto the back of the tank made me vulnerable to turning belly up again and I had to move all my remaining weights front side to counteract it. My feet were still dipping.

I’m now thinking that due to my trim issues I must be constantly counteracting my negative feet in order to maintain my horizontal position in the water and look ok doing it. So this must be affecting my buoyancy.
Is my Buoyancy control there for artificial? I’m thinking I’m probably negatively buoyant and using my legs to push up to maintain neutral and level my trim at the same time.
Once I get my own kit I plan to spend some time in a pool somewhere with a camera to see how I am

Any tips on trim and whether I would be best suited to a wing or BCD as my first BC purchase would be much appreciated? I don’t plan on getting tech but will develop my training and certifications over the coming years.

[Stevie H]

Why couldn't you have started this thread yesterday???

[anvill72]

Re: Buoyancy vs trim vs BCD vs Wing

I also have feet that sink all the time and cannot hold the "horizontal, legs slightly bent" position whilst remaining still. If I stop finning, the legs drop.

I've moved some weights to the trim pocket of my Oceanic Biolite but this atill did not solve the problem.

I'm guessing it will come from experience. I don't think your buoyancy is "false". Just like me you have heavy legs. In my OW course there was a student with very floaty legs who required a large amount of ankle weights in order not to get upside down involuntarily.

[anvill72]

Re: Buoyancy vs trim vs BCD vs Wing

Why couldn't you have started this thread yesterday???

I'm guessing OP wasn't trying to start a ruck ot otherwise endless and pointless discussion about horizontal trim, but was just looking for advice on how to achieve the horizontal trim he wants to have.

[Spirit of Guernsey]

A wing for sure, plenty of people like me with BCDs in the shed.

If you can, book a day with Mark Powell or Garf to sort out your trim, shouldn't be a problem for them.

[Graham Smith]

A wing for sure, plenty of people like me with BCDs in the shed.

If you can, book a day with Mark Powell or Garf to sort out your trim, shouldn't be a problem for them.

Spot on.

A wing will "Suspend" you in the water while a BCD will "Support" you in the water (think where the buoyancy is in a wing in relation to your body, and a BCD, which often has lots a buoyancy around the front of the jacket, which can tend to pivot your legs downwards as the jacket lifts). A wing will also give you more options over where you want the gas to be in the bladder, rather than where it has to be in a BCD.

I think a great deal of you "problem" (I don't see it as a problem, but a learning curve still) might be your perception of "Horizontal". Have you referenced yourself against anything you know to be flat and horizontal in the water? Even staying a couple of inches off the bottom to get a "Feel" for what is flat?

While I know many people who have attended workshops with Mark and Garf may have sworn that they were "Feet Light" and needed ankle weight, the vast majority come away without them. I think the same may apply to you in reverse....

Best of luck with it.

G

[SonicStomp]

Buoyancy vs trim vs BCD vs Wing

If I had my time again I would go straight for a wing. I, like many, grew up diving a buddy BCD and discovered a wing recently. It makes a big positive improvement over the jacket.
I still have my buddy and will continue to use it until I get a single tank wing (my research is leading to me towards Halcyon eclipse. )

[Graham Smith]

I still have my buddy and will continue to use it until I get a single tank wing (my research is leading to me towards Halcyon eclipse. )

If the H's are a bit pricey, try Dare2Dive gear - almost identical, fantastic quality, and much cheaper. DTD - Dare to dive


G

[SonicStomp]

thanks - I've got to get my twin setup squared away first....i've just been on a course where I dived a Halycon Evolve system and I am a convert....I have a shiny(ish) pair of twin 12 fabers to marry to a new wing....which means using the buddy for a while longer on my single 15...

[SonicStomp]

Just looked at DTD - some excellent prices there..thanks for the tip.

If the H's are a bit pricey, try Dare2Dive gear - almost identical, fantastic quality, and much cheaper. DTD - Dare to dive


G

[Kermit]

I use a wing but, for buoyancy there's not a lot of difference between a wing and a bcd until you start carrying a lot of gas. The concept is to be neutrally buoyant at 3m with an empty tank. Extra gas needs to be added to compensate for the weight of gas you start your dive with (about 2kg of air in a full 12??) and the compression of a neoprene suit (drysuit or wetsuit) at depth.

I use a membrane drysuit and find that I can adjust my buoyancy when using a single cylinder quite comfortably just adjusting the amount of gas in the drysuit, other people use a constant volume drysuit and adjust with a bit of gas in the wing/bcd. Either way is suitable as long as it suits you.

The point is there aint a lot of gas in your wing/bcd even if you are using it as your sole method of buoyancy adjustment. With me, there is no gas in my wing unless I'm sitting on the surface. If you still have gas in your wing/bcd with an empty tank at 3m then you are overweighted.

Trim is a different thing completely. This depends on WHERE the weight is situated. Moving your tank up and down in the straps has a large effect. Also, think about where your weights are situated. For me, I have weights in a pouch by my belly and some strapped to my tank. This is just a personal thing, the important thing is that I know exactly where to position my tank and weights to get the trim I want and I make sure everything is in the same place (exactly) whenever I dive.

An underwater camera is a very handy tool. How you feel your trim is in the water can be very different to how it actually is as shown on a camera.

Best of luck,
kind regards
Ian

[o2dependant]

Thanks all!!

I think I will go with the wing as even though I did use it a handfull of times I just felt like we had a better connection.

Once I get all my gear I will likely get a day in with somone who can help me fine tune things.


Was not aware of the friday ruckus!!

[Graham Smith]

Was not aware of the friday ruckus!!

It's an old tradition from "The other place". There are some fairly contentious topics such as using a Pony, Wing v BCD, BCD v Drysuit for buoyancy, and many others.....All guaranteed to start up a heated debate otherwise known as "The Friday Ruck".

This thread (and topic) looked an ideal candidate for a Friday....

G

[Regthing]

A wing and back plate is also good as the weight of the back plate will replace some of your lead, for dry suit diving get stainless steel, not aluminium. It also places the weight higher up your body and closer to your centre of gravity.

There are also weights available that fit in the groove of the back plate, between twin sets, in pockets on can bands etc that allow you to position the weight where you need it to achieve the trim you want.

[ootini]

I now dive a plate, oph, wing and twin 12s. In fresh water I need no extra weight, in salt I stick two small shotbags in pockets on the waist band. I love the lack of clutter and shit in front of me when using a wing/oph compared to a traditional bcd.