Noob questions about various weight(s) topics .....

[went_postal]

My very first post !!!

I'm brand new certified OW and only have 2 real post training dives. (Holy cow Kyalami Divers in West Palm Beach was crazy awesome)

I have a few questions about weight(s).

1. It seems to be a hot topic to have the least amount of weight on you as possible. Even a bunch of advertising has how light such and such part is. What's all the lead hate about? Is it really going to kill you to have one extra puff of air in your BCD ?

2. When am I ever going to "drop weights"? I hear all the talk about not ascending too fast. That seems counter to my lessons. What is a real world example where you had to drop weights? Wouldn't it possibly be a problem if you accidently dropped weight out of a quick release pocket? It seems more logical to have permanent weights with only a very small amount of releasable weight. Even then I cant think of a real need.

3. Why do I care if my 1st stage is light and compact? Wouldn't that make it less durable?

Thank you for asking these questions. This has been a topic brought up at the local dive shop a few times. So this has been on my mind a lot lately.

In Fresh Water I've been using ~12 lbs in rental rigs. Last time I tried to submerge I actually had to fight to get down until my suit compressed.

The shop owner seems to think I should be able to get away with 6 lbs. I dunno... In a pool with no suite I don't need any weights... So I am going to assume part of my "issue" is my 3mm suit may not be the best fit and has too much air in it (its not super tight because I can't stand when they are super restrictive).

With 12 lbs at ~35 feet I have an empty BC and I am not crashing into the floor. I go up and down with my breath. To me that sounds about where I should be.

With salt... you are going to be more buoyant... so it would seem I would need more weight and not less.

Someone asked about training about blowing bubbles in the way up... They taught it to us... we had to do CESA to pass OW with SDI.

 

[inquis]

With salt... you are going to be more buoyant... so it would seem I would need more weight and not less.

Yes, based on average salinity, these are ballpark adjustments to fresh water weighting for single-tank diving in salt water, based on your body weight. Add 5 lb (145-190 lb), 6 lb (190-230 lb), 7 lb (230-270 lb).

These assume about 40 lbs of gear (incl. tank), but a few lbs more or less won't change things appreciably, as it's about 0.25 lb lead for every 10 lbs of diver/gear mass.

 

[inverse_suit]

Was searching about weights etc and found this thread, I hope that this is the right place for my question. And yes, it may be kind of a stupid question, sorry about that.
If I understand correctly, one should be able to empty the bcd completely on the surface (at the start of the dive) and be able to start sinking slowly just by breathing out. right?
so if I would breath in and out with an empty bcd, I would remain on the surface (at eye level).
that would only happen if I'm weighted perfectly.
this would mean that I don't have any possibility to use my bcd if I would like to sink more during my dive, since I deflated it completely at the start of the dive and control my buoyancy only with my lungs.
(assuming that I don't have to put air in my bcd during the descent, of course).
am I getting this right?

 

[boulderjohn]

so if I would breath in and out with an empty bcd, I would remain on the surface (at eye level).
that would only happen if I'm weighted perfectly.

You should float at eye level while holding a normal breath. If you exhale, you should sink.

 

[inverse_suit]

great! i think that was exactly where my confusion came from, missed the „holding the breath“-bit.
and is there a connection between the check at the start of the dive and the check during safety stop at the end?
like: i‘m fine at check 1 so check 2 will be ok, too?

 

[therookie]

great! i think that was exactly where my confusion came from, missed the „holding the breath“-bit.
and is there a connection between the check at the start of the dive and the check during safety stop at the end?
like: i‘m fine at check 1 so check 2 will be ok, too?

The difference between those two checks can be surprising. I find that there is only so much "fine tuning" that I can do with a weight check at the start of a dive, which personally I only do at on the first dive of a dive trip (I'm a strictly vacation diver) to get a ballpark and make any "temporary" adjustments that I need to.

The weight of the gas consumed during as well as the fact that the 3mm shorty wetsuit that I use has slightly different buoyancy characteristics between when it is still dry at the start of dive compared to when it has been underwater for nearly an hour at the safety stop make that first check not something I can fully rely on.

So the "safety stop" check (which I generally also do only once at the start of a dive trip, unless I've been fighting with my buoyancy on the trip) is the only one that I find gives me results I can really work with. I don't yet have the experience to do the kind of breath control between top of lung and bottom of lung that more experienced divers can do, so I want my weighting at the safety stop to be such that I don't have to think about it in case I'm task loaded with something like shooting a DSMB or, far more common in my diving, blowing bubble rings or scanning for eagle rays and dolphins during the safety stop...

 

[lowwall]

Was searching about weights etc and found this thread, I hope that this is the right place for my question. And yes, it may be kind of a stupid question, sorry about that.
If I understand correctly, one should be able to empty the bcd completely on the surface (at the start of the dive) and be able to start sinking slowly just by breathing out. right?
so if I would breath in and out with an empty bcd, I would remain on the surface (at eye level).
that would only happen if I'm weighted perfectly.
this would mean that I don't have any possibility to use my bcd if I would like to sink more during my dive, since I deflated it completely at the start of the dive and control my buoyancy only with my lungs.
(assuming that I don't have to put air in my bcd during the descent, of course).
am I getting this right?

You can't do a good weight check at the start of a dive, only at the end.

The problems with doing it at the start of the dive is that you have several pounds of air in your tank that you won't have at the end. Offsetting this are any air bubbles trapped in your suit or gear or even on your skin that will get worked out over the course of the dive. This latter amount is highly unpredictable if you are wearing anything other than a bathing suit.

 

[boulderjohn]

You don't have to fine tune your weighting to the degree many would suggest, and you really don't want to. If you do the suggested weight check at the beginning of the dive, add some weight to account for lost air during the dive and just to be safe--a few pounds over ideal weight is more than acceptable; a few pounds under ideal weight is not. On an NDL dive, I am usually a few pounds over ideal weight, and I assure you I am probably the most perfectly weighted diver on the boat.

 

[inverse_suit]

I appreciate all your answers, thanks!
All clear now for me.