Keeping the heavy parts and light parts together?

[carbon]

This might be a silly question....

I dive with a 7 mil wetsuit, hood, booties, and gloves. During my O/W class, we got into the pool wearing only the above gear (no weights or tank). It was a comical, all of us were so buoyant we could barely maneuver, but it was a very effective demonstration of neoprene buoyancy.

In open water, I wear 30 pounds of weight on a weight belt. This much weight makes my back a bit sore. So, I've been thinking about a BCD with an integrated weight system.

Here's the silly question:

How do integrated weight divers keep from rocketing to the surface if they have to don or doff their BCD underwater? If all (or most) of the weight is with the weight integrated BCD, do you just hang on for dear life?

Thanks,
Carbon

 

[Dryglove]

From what i have discovered with neoprene is that after about 15-20 ft your buoyancy changes dramatically.By all means dont let go of your bc while your fiddling with it.

I know some people that wear both and split the weight between their belt and integrated weights.

Im not exactly to sure why you would need to take your bc off underwater.If your tank slips loose or you get an entanglement thats what your buddy is there for.

If you are really worried about it get some pockets put on your wetsuit.If the need arises remove the integrated weights and place them in your leg pockets till your all fixed up.Then dive on.Later!!

 

[Uncle Pug]

Have some on the belt and some on the BC...
That way if you do need to remove the rig it won't sink while you rocket to the surface...

You are ahead of the curve in thinking this through and asking the question... many integrated weight divers haven't a clue.

btw... a 6# SS backplate/wing is not only the most comfortable rig to dive it is well balanced and adds just a touch of extra weight to the rig. You can get heavier plates or even a weighted single tank adapter that will increase your rig's weight into the 12~15# range and that will allow you to wear a minimal weight belt that would be enough to keep you down at 33' in the scenario you refer to.

 

[carbon]

Thanks for the recommendation to distribute the weight. That is exactly my goal.

However, if my wetsuit has tremendous lift on its own, shifting weight to a BCD or backplate/wing rig still makes donning or doffing the rig underwater a "thrilling" proposition. "Luke, be one with your rig".

Do integrated weight divers never doff their gear? Do DIR rigs always stay on the diver?

Am I making too much of this?

Carbon

 

[Dryglove]

For one you have to remember that your wetsuit compresses with depth and wont be nearly as buoyant as it is on the surface.

I personally have never had to remove my bc underwater.I dont do cave diving or wreck penetrations(not yet anyways)

I almost always dive with a buddy.

I dive with a scubapro knighthawk(someday will be a halcyon bp and wing) with fully integrated weights.

If for some reason i am diving solo or buddy is not around ill take an integrated weight pocket and place it in my drysuit pocket.

When you go through some further training you may be required to swap your bc with your partner underwater.Kinda sucks if your buddy is a lot smaller than you.

I dive mostly in the kelp beds of monterey and surrounding areas which is an entanglement hazard on its own if your not paying attention.

Is there any particular reason why your so interrested in this subject or is it just for good measure and future preparation.If it is good for you.Always think and plan ahead.

 

[Uncle Pug]

Originally posted by carbon
Do integrated weight divers never doff their gear?
Do DIR rigs always stay on the diver?
Am I making too much of this?

1) Not without holding onto something.
2) Yes that is preferred.
3) No, you are thinking and that is good.

Carbon when you are at 33 fsw your 7mil wetsuit only has half the buoyancy that it did at the surface. That means that you only need half of the 30# on your weight belt at 33 fsw. That means that your BC needs to compensate for the other 15# with air. That means that if you are wearing 15# in a belt and your BC is *wearing* 15# integrated then you are both neutral at 33 fsw. Ideally you would be able to take your BC off and have it float neutrally beside you at 33 fsw (however things seldom work out so neatly in real life.)

Would you ever need to take off your BC at depth? I never have but I can imagine several scenarios where it might be advantageous. But there is a more compelling reason to have a balanced rig:

During a dive all you need your buoyancy compensator for is to compensate for loss of buoyancy caused by suit compression and increased buoyancy because of air consumption. You have already learned that you do not need it for diver floatation at the surface... your wetsuit is more that adequate in that regard. However should you take the rig off at the surface the BC must be capable of supporting the rig or it will sink.

How much *lift* the do you really need in a BC.... well if it has to carry all the weight (integrated) then you will need enough to float it with a full tank at the surface.

But if you have some of your weight in a belt... say 15#... then you will need much less *lift* capacity in a BC and that means a BC with less drag. Of course many of the uninitiated think more lift is a *feature* and purchase a BC as big as a blimp... if this is you then stop reading now...










For those with understanding:

A backplate mated with the smallest practical wing gives the least drag while providing sufficient lift for the rig and plenty of compensation for the gas used during the dive. A wing such as the Halcyon 27# wraps up around the tank part way and produces such minimal drag that I can kick once and then glide through the water. Try that with your BC. If I were using weight integration I would need a larger wing like the 36# or even the 45# to support the rig with full tank at the surface if I should take it off. Since I carry some of my weight in a belt the smaller wing works just fine. If this does not make sense but you are interest feel free to ask specific questions. I dive a drysuit... YMMV in specifics.

 

[The Chairman]

Hey carbon,

I agree with the Pugster that you should try to be as balanced as possible. However, you can have all of your weight on your rig and still "cope". When I dive my steel doubles, I never use additional weight... they are all I need. When I have to doff and don the tanks I simply do the "roll". Right arm in first and then just roll your body around like a gator with a fresh kill. The BCD will wrap around you and then you just finish the job by putting your left arm through and fastening all of your straps. I can do this suspended off of the reef so there is no environmental impact. There are other ways, and I suggest you experiment in a pool or safe area BEFORE you need to do it for real in the open water. I have had to do it for a fishing line tangle that I just could not reach with it on.

 

[MikeS]

I am relatively new to diving and have a balance weight integrated back-inflated BC. I have had no problem donning or doffing (is that a word?) my BC either at the surface or under water. The key is don’t let go! I found this intuitive; for me it was only natural to hold on to the BC as it tried to sink and I tried to shoot to the surface.

I think that a separate weight belt would only complicate the situation. If you took off the weight belt and BC, the weights would sink, you would float, and the BC would either sink or float depending on its buoyancy.

While you’ve raised a valid concern I think that if you gave it a try you’d find it is not that difficult. It doesn’t take much effort to hold onto the BC. Perhaps it’s personal preference but I find it easier to put on the BC in the water if it’s negatively buoyant. At the surface I let out enough air to make is so before trying to put it on. It was very difficult to put on at the surface when positively buoyant.

Mike

 

[rcohn]

On this topic (as an example of what not to do) check out, I Guess It Wasn't My Time To Die by Art Laramee in http://www.neadc.org/newsletters/neadc_news_08-2001.doc

I'll just pretend I'm not a member of the same dive club.

Ralph

 

[carbon]

I think this board is awesome!

I finally got my "nagging" concerns addressed:

1. How to dive balanced, and control it.

2. The importance of be familiar with the equipment so I don't do someting dumb under normal, stressed, or panic situations. Ralph's link to Guess It Wasn't My Time To Die by Art Laramee sure hits home.

Thanks to each of you!

Carbon