Mystery - Forward propulsion
- Thread starter ccrprospect
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OP
ccrprospect
Contributor
Wetsuit. As to weight, varies by thickness and whether I am diving steel or aluminum. I would say I use 50% more weight than peers with comparable setups. Why? Never really knew. Best guess is due to a gigantic wing which tends to trap air pockets and which makes holding deco stops with less weight uncomfortable or even unsafe.
OP
ccrprospect
Contributor
Well if you know of a wing that has high lift capacity (sufficient for “advanced trimix” dives with 5 tanks) while being relatively streamlined, please do recommend. Preferably with dual bladder as I don’t dive drysuits.
GreggS
Contributor
It really isn't about changing wings, it's more about getting your weighting right. Since you have over 100 dives, I would assume you are aware that the more weight you add, the more air you have to add to your BC. The more air, the more drag. Ideally, you should only carry enough weight so that you only have to add a minimal amount of air once you get to your dive depth in order to maintain proper buoyancy. Not only does this help in taking less energy to kick and get better forward momentum, but it should also reduce the amount of air you use. If you are kicking like crazy to keep up with others that are doing it effortlessly, you are having to breath heavily.
Start by reducing the amount of weight you are carrying by a couple of pounds until you get used to it, then try reducing a couple more until you get down to where you are not having to add a lot of air to get buoyant. If you are familiar with the weight test (500 psi of air, floating at eye level with no air in BC) try that as well. I think you'll find you are using way to much lead.
Start by reducing the amount of weight you are carrying by a couple of pounds until you get used to it, then try reducing a couple more until you get down to where you are not having to add a lot of air to get buoyant. If you are familiar with the weight test (500 psi of air, floating at eye level with no air in BC) try that as well. I think you'll find you are using way to much lead.
OP
ccrprospect
Contributor
If I don’t add that much air at the bottom, doesn’t this portend difficulty holding deco stops on ascent? In other words, and even allowing for some gas expansion, there won’t be much of anything to deflate to control the ascent.
GreggS
Contributor
Not really. Everything is relative. More weight, more air in the BC. Less weight, less air. That's why the buoyancy test I mentioned earlier is a good tool to use. At the end of a dive, with 500 psi in your tank, try to float at the surface with no air in your BC. If you can float at eye level with the water surface, you are good to go. If you sink, you have to much lead, if your above eye level, not enough. You also have to remember that the deeper you go, the more your wetsuit compresses thereby reducing its positive buoyancy and the need for so much weight. And since it has had the air squeezed out of it by the pressure of the water, it won't be as buoyant when you ascent as it was when you descended. Naturally, if you change your set-up, such as go to a thicker or thinner wetsuit, for example, you will need to change the amount of weight you carry to compensate.
If you do find that you are struggling to hold a deco or safety stop, then simply add a pound or 2. It doesn't take a lot to make a big difference.
Take me for example. When I first started diving, I was using 16 lbs of weight in fresh water with an 80 AL tank, 3mm wetsuit, boots, gloves, and hood. Now I'm using 8 lbs. For salt water, I have to go back to 14-18 lbs depending on where I'm diving. Salinity differs in different parts of the ocean.
If you do find that you are struggling to hold a deco or safety stop, then simply add a pound or 2. It doesn't take a lot to make a big difference.
Take me for example. When I first started diving, I was using 16 lbs of weight in fresh water with an 80 AL tank, 3mm wetsuit, boots, gloves, and hood. Now I'm using 8 lbs. For salt water, I have to go back to 14-18 lbs depending on where I'm diving. Salinity differs in different parts of the ocean.
You already said:
this wing is very big (how big is big? brand/model?)
the wing traps gas
you have roughly 50% more lead that your buddies carry
All of that equals a big flappy wing, and if you are slightly out of trim is gets even worse.
So I think you found out why you are having to kick so hard to keep up with them and burning through gas in the process.
AL80s full of high helium trimix suitable for 5 bottle dives don't weigh anything in the water even when full. You don't need a big wing to float bottles of 15/55 or 12/65. Full with a reg on them they are barely negative at all. Empty they are buoyant.
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