Was I over weighted?

[cannon fodder]

I went out to Dutch Springs today with a new dive buddy I met. I did my first dive in a 7mm jacket over a 5mm full with 28 pounds, 2 pounds less than I did my AOW in with the same suits in May. After a short and definately over heated dive, I took of the jacket and went back in with the 18 pounds, 5 in each dumpable pocket and 4 in each trim pocket, 5mm full suit. We went down and after a while I felt like I was torquing, twisiting to one side, but I didn't lose bouyancy control. The dive continued and sudenly I was head down, the torquing stopped, but I lost trim. Still decent bouyancy. When I got up I realized that the weight pockets were twisted out, I still had them, but the two 5 pound weights were gone. I went from 18 to 8 in a single dive and just let air out of BC or lungs without thinking about it and and continued on. I did another dive with 8 pounds, and while it was tricky getting down, I managed. This was a real eye opener for me, to lose that much weight, over 50% without popping up or even noticing that much. The last dive felt a little light, but I may go to 10 or 12 pounds in the same conditions and wetsuit, but not back to 18 and I will definately start taking weight off on other dives. Any comments on this? Being grossly over weighted and not realizing it until the weights fall out?

 

[PeterNBiddle]

Yes, you were (grossly) overweighted.

I've witnessed the hunchback situation you described and it was due to overweighting.

 

[dfx]

Quite typical I'd say. With a full 5 mm suit, I use 18 lbs of lead in salt water (and even that's a little bit too much).

It's perfectly possible to have way too much weight on you and still have good buoyancy control. It just makes it harder to do so. The way to measure it is at the end of the dive: with a nearly empty tank, you want to be neutral with an empty BCD and close to the surface. A good time to check is during your safety stop, assuming your tank is getting close to empty. Let all the air out of your BCD, stop moving and observe. Dropping like a rock? Too much weight. Floating up? Not enough weight. Neutral or maybe just sinking a little bit? That's about right.

Problems getting down at the start of the dive, even though you think/know you have enough weight? Relax. Make sure you really have all the air out of your BCD. Relax some more. Breathe out. Let yourself drop. The natural response to sinking below the surface is to gasp for air and retain it in your lungs. That's what's keeping you afloat.

 

[spectrum]

Personally in MY case, fresh water, 5/4mm Bare Velocity, Freedom plate and #30 wing and HP-80 cylinder I use 4 pounds. A jacket suggests adding about 4 pounds and I'll guess you have an aliminum 80 cylinder so add 6-7 more pounds. That being said projecting from what works for me something near 15 pounds would not surprise me. There are other puts and takes that could alter this and again it's based on ME.

The big takeaway is that you recognized the potential for a dramatic weight reduction. Now plan to do some good weight checks so you can dive ynd safely with minimal weight. Much more here.

Pete

 

[Eric Sedletzky]

At the end of a full length dive with the PSI of air that you normally end your dive with, you should be able to hold a 15' stop with no air in your BC and control your stop with your breathing alone. This is perfect weighting. Any more than that is excess weight that doesn't need to be there.

 

[Crowley]

Definitely sounds as if you were overweighted to start with. A classic giveaway is that you end up moving much more up and down in the water. Neutral buoyancy is still possible to achieve, but buoyancy control is much harder, and it doesn't matter how experienced you become, there is a point where you simply cannot defy the laws of physics.

When you are correctly weighted, you need to use technique to descend, and this should not be easy at the end of the dive with a light tank. If you are correctly weighted, then yes - as per the advice above, you should float at eye level with an empty BCD whilst holding a half-lungful of air. When you exhale, you become negatively buoyant, when you inhale, you become positively buoyant, and therefore we end up with the classic diver unable to descend because they keep breathing in and out. At the beginning of the dive, especially if you're diving with an aluminium tank, you will be slightly overweighted and the descent becomes easier.

There's plenty of good advice in these forums about correct weighting (and some pretty crappy stuff, it has to be said!!) But once you get it, it's an awesome feeling!

Good luck,

C.

 

[DivemasterDennis]

As noted above, the answer to your question is YES. If you have to ask....you are probably overweighted. Too many divers are too cavalier about proper weighting. As you read threads on the subject, you will learn more. Remember to factor the difference in buoyancy of a full tank vs. a depleted tank. Remember that weighting depends on your weight and body type, and changes there impacts proper weighting. As you now know, equipment changes impact proper weighting as does water type ( fresh vs. salt) and location (as salinity varies). There is a HUGE difference in diving when properly weighted as compared to gross over or under weighting. Keep a log of every dive noting location, conditions and equipment worn and proper weight used, and you can refer to it for future dives. It's a great tool. But take time weight properly so that your log is one of proper weighting, not over weighting.
DivemasterDennis

 

[herbdb]

Next time you you at Dutch, divide your weights and put a couple of small weights in a pocket. Then at the end of your dive, find a nice spot at about 15 ft and remove the weights one at a time and set them on the bottom. You will be able to find out exactly what you need to hold your safety stop.

 

[cannon fodder]

Hi Guys,

Thanks for the comments. I think I need to add a couple pounds on, but not all ten for sure. Frankly one thing that I was trying to work on was my breathing rate. I am going to work a little more on weighting, and see if that helps with SAC. I can do bouncy better now at 20 dives then I did after only a couple, but it does take quite a bit of concentration. I have had comments about swimming head up, and with 8 pounds I was swimming head down. Hopefully better weighting will allow me to keep my trim in balance and not be swimming up to counter over weighting. I spoke to my new buddy and he wants to try Brownstone next, in a couple of weeks, so I will have a chance to put my lesson into practice soon.

Cheers,

Derek

 

[Dr Neil]

You indicate your wetsuit thickness and what type of cylinder you had, but what about your body weight?

A formula I learned from my OW instructor many years ago give a diver a good starting place:

body weight X 5%
add 1 lb for every mm of thermal protection on the torso
add 4 lbs for an al80 tank (other tanks will either add or subtract from the calculation)

It's a simple formula but it puts a diver in the ballpark for how much weight they should carry.

Novice divers tend to need to add a pound or two. Advanced divers tend to shed a pound or two.