Feet Heavy

[DandyDon]

Just out of curiosity, do you use a back inflate/plate&wing or a jacket style bc?

Good point, as a plate would add weight.

But I was responding to the statement that he had difficulty getting down, ergo he'll have more problems staying down later.

​

 

[Green_Manelishi]

Last Weekend I dove in cold water for the first time 65 deg.

65 degrees is cold water? I think not. I did my last wetsuit dive of the year this past Sat. The water temp was hovering around 50/55. Time for drysuit.

As for the feet heavy try pulling them "up and back" toward your glutes. If you stay "straight out" like an arrow with your legs fully extended that will aid in being
"feet heavy".

 

[crpntr133]

I am having the same problem. Question...an AL80 is positive through the entire dive, right? If so then why shift the tank to your head? If you shift it towards your feet then your feet should float..yes/no.

 

[STOGEY]

Because of work,

The last time I dove was about 4 weeks ago. I have two sets of tanks one set is the pressed steel variety, the other pair given to me are of the aluminum varitey, just like the ones that you would probably rent at a vacation spot. Anyways as far as bouyancy is concerned or trying to achieve less positive bouancy, I found that I had the same problem as you did.

I am 5'7" and weigh about 200 lbs. Did I mention that I live in a terrible cold climate where the water temperature rarely gets above 65. I use a wet suit that is 7 mils thick.
On the pressed steel tanks about 30lbs of weight is usually sufficient in attaining negative bouyancy. When I use my aluminum tanks, if I don't add an extra 5 lbs I have a not a real hard time achieving negative bouyancy, but more then with the steel ones.

I've found that if I change the attitude of my body that is point my upper body downward I have an easier in achieving a easier descent. I know that when we went through our intsruction they taught us to descend feet first, but I'm a big boy and I think that if I descide to use my head before I use my feet well. Sometimes that actually even works.

 

[DandyDon]

I am having the same problem. Question...an AL80 is positive through the entire dive, right? If so then why shift the tank to your head? If you shift it towards your feet then your feet should float..yes/no.

A stadard 80 Al will become increasingly positive as the pressure inside drops. Fewer air molecules taking the same space. One source (Diver's Direct magazine I have handy) suggest that a Standard 80 Al starts off as 3.4# negative and moves to 2.5# positive, virtually a 6# difference.

I think shifting the lead forward is going to have a bigger impact. Look forward to testing that in the practice pit.

 

[Bonnet Ray]

I've always been feet heavy until I started added weight to my rear pockets (by the tank) and now I'm horizontal. The difference on the first dive was amazing . I've tried all sorts of different leg positions but having the weight on the tank has been the only solution. Give it a try I hope it helps.

 

[MikeFerrara]

A stadard 80 Al will become increasingly positive as the pressure inside drops. Fewer air molecules taking the same space. One source (Diver's Direct magazine I have handy) suggest that a Standard 80 Al starts off as 3.4# negative and moves to 2.5# positive, virtually a 6# difference.

I think shifting the lead forward is going to have a bigger impact. Look forward to testing that in the practice pit.

The magnitude of the buyancy shift is due strictly to the capacity of the tank and what gas you're talking about. An 80 cu ft tank used with air will be about 6 pounde more positive empty just because 80 cu ft of air weighs about 6 pounds.

A steel tank may be more negative empty but the change in buoyancy from full to empty will be the same for the same amount of the same gas.