Buoyancy
- Thread starter Jeffr13
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I want to thank everyone so far for helping a new diver out. I'm going to try using some different weight/buoyancy fins and added trim weight to tank valve or shoulder straps. The real problem is being in the midwest, I can't just go out and try out a lot of stuff. I may take some additional Adv. course but they will be in April in very cold water at a Mermet Springs. I'm going to request 1st focus on the Peak Buoyancy. All my dives to this point has been in 7mm, and its going to be cold again if I go in April. I thought about doing the drysuit but since I'm going to Florida a few months later. Would it be best not to complicate things? I could just do the enrich-air, that my friend in Florida suggested.
Again thanks everyone for all the help.
JeffR
Again thanks everyone for all the help.
JeffR
If you see yourself diving locally in a 7mm in the future, it's perfectly fine to take your 7mm with you to Florida to work on bouyancy and trim. The weight works the same in warmer water, and you can always pull open the neck of the suit to flush with water if you get hot. It's also fine to go to Florida, have fun diving in a lighter suit, and kick the drysuit can down the road. But either way, I strongly endorse going to Florida and giving yourself a break. Diving is supposed to be fun!
mcohen1021
Contributor
I'd be exhausted if i dove with ankle weights... lol
With as little weight as I use today, I do not use the integrated weight pockets anymore, only the tank pockets. Much better than being face down topside.
With as little weight as I use today, I do not use the integrated weight pockets anymore, only the tank pockets. Much better than being face down topside.
pauldw
Contributor
I don't get it. Assume I'm stupid and spell that out a little for me, please.
Steel are negatively bouyant, aluminum are positive. Consider the cylinder band as a fulcrum and the tank as a lever arm. Steel pulls the long end down, aluminum pulls the long end up.
pauldw
Contributor
Mine has two tank bands, so I'm magically trim!
Here comes my stupidity showing again, but I've never grasped this. A tank weighs what it weighs. Maybe it's heavy steel, but then there's less lead on the weight belt. If two tanks have the same amount of air in them (and I know steel probably has more, but that just makes things even more confusing) then the air in each of the tanks weighs the same, so when it's gone the tanks should each weigh the same amount less. If the divers breath the same amount from each tank. So how does one tank (steel) go from making a diver negatively buoyant to making a diver neutral, and the other (aluminum) goes to making a diver positive, if they're each losing the same weight of air?
johndiver999
Contributor
That's true AND if you are using a big steel tank and use a greater volume of gas, you will get a larger buoyancy swing than with an 80 tank.
However, when an aluminum gets really low and starts floating, it often feels really different. You can feel it pulling up and if you don't have integrated weights, the whole BC can starting lifting off of your body (a little). This is not a big problem, but it is a different sensation and some people seem to be more averse to it than others.
However, when an aluminum gets really low and starts floating, it often feels really different. You can feel it pulling up and if you don't have integrated weights, the whole BC can starting lifting off of your body (a little). This is not a big problem, but it is a different sensation and some people seem to be more averse to it than others.
Because even if they both changed by the same amount over the course of the dive, the steel cylinder started out MORE negatively buoyant than the aluminum cylinder. Here are some specs for you to look over. Note that in these examples, the steel 80 starts out -8.05 lbs negative when full, while the aluminum 80 starts out -1.5 lbs negative.
Faber Hot Dipped Cylinders — Sea Pearls
metal impact aluminum cylinders — Sea Pearls
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