ditchable weight w/BP+wings

[scubaguy90250]

I have been reading many of the old post's and I know this topic has been beaten to death, BUT,,,,,, I am interested in switching over to a Bp+wings setup, But I have a ? about ditchable weight?

If most SS BP's weight about 6 lbs, and my Steel 120 weighs about 7 lbs neg, that doesnt leave much IF any weight needed, and im concerned about NOT having any weight thats ditchable?

How do others deal with this?

I dive In a dry suit and a steel 120 cylinder. I go down with about 10 lbs, on ocasion Ill need 13 lbs.

Oh, yea, I also use 1 lb each Ankle weights So that will bring it up to 15 lbs.

But If I switch over I wouldnt need practically any weight?
This cant be safe? what gives? Do I just dive over weighted?

Or is this BP+wings setup, just not for me?

 

[JessH]

13 pounds non ditchable is a lot IMHO. You may want to go with the aluminum bp which is only about 2 pounds. Is the 10-15# you are listing including the weight of the tank or not? If not then you should still need some ditchable weight, but still might not be as much as you would like.

~Jess

 

[Wendy]

You could always get an AL bp insted of the SS.

 

[Doc Intrepid]

then this will sound like deja vu all over again , but:

1. Many divers dive without ditchable weight. The scenarios in which you would need to drop weight AT DEPTH are extremely rare. In these cases there are other options. Be able to swim your rig up with the correct amount of weight.

2. Calculate how much (additional) weight you will need to effortlessly hold a 10' safety stop with no air in your wing/BC, drysuit, and very little left in your tanks (~300-500 psi).

3. Whatever this amount of weight is, it will generally be spread between your backplate and lead. The lead can take the form (for a diver using a single tank) of either a trim weight or channel weight attached to your backplate, or a weightbelt. [Lose the ankle weights.]

4. The function of the weight spread should be to optimize your ability to maintain control over your bouyancy and your trim. You should ideally be able to stop swimming and hang motionless in a generally horizontal, neutrally bouyant configuration. You select SS bp, aluminum bp, trim weights, or weightbelt according to how much weight you need to achieve this goal, and where you need it positioned to achieve this goal.

5. By virtue of the fact that you are perfectly weighted at the END of your dive, you will by definition be over-weighted (by the weight of the compressed gas in your tank) at the START of your dive. This is not bad.

6. Caveats are that you should (a) have a redundant source of bouyancy (you do - your drysuit); and (b) you should be able to swim the weight of your rig at the START of your dive (e.g. at its heaviest) to the surface.

7. Even though you are recreational diving with a single tank, and I assume no-decompression limits although you did not specify, you ought to be getting into the habit of holding a 10' safety stop for 3 minutes during every ascent. If you drop any weight at depth you will afterwards be unable to hold this stop, since you weighted yourself specifically to be able to do so. This is one primary reason that you should not drop weight at depth. There are others, but this should cover the matter sufficiently.

Hope this helps.

Doc