Questions for all of you SoCal Vets

[dgallo]

MaxBottomtime nailed it on the head with regards to buoyancy and experience.

Your breathing rate and movement has a direct effect on your buoyancy. More movement = heavier breathing = more buoyancy.

The yoga classes are going to help you a lot. A friend of mine swears that it doubled her bottom time just due to air consumption.

If you take some extra time at the beginning of the dive to relax after the surface swim, then relax on descent and then take a few minutes once you get down to relax into your breathing you will see a lot of difference.

Spend a few of your next dives really paying attention to your breathing. Make a conscious effort to exhale as completely as possible, then inhale fully - see if you start getting a fin pivot effect. Get in the pool and play with your buoyancy as well.

Getting used to what heavy and light feels like helps. Breathe your tank down to about 300 and see how much lighter you feel. Tuck your hands in the cummerbund of your BC and try and swim around and do everything without adjusting by flapping around.

You could take the peak performance buoyancy class, but a lot of it can also be solved by getting some extra weights and experimenting with a buddy.

 

[scottfiji]

Scott,
The last time I used 26 pounds with my BC and 2 piece wetsuit in Casino Points. I have to hold on the rope during my safety check (15 feet). With 500 psi and my BC fully deflated, my tank is still pulling me up. The next dive I added 2 lbs, and I was fine. I know for sure my BC has a lot of inherent bouyancy. I tested it in the pool and I read a Rodale review that concured this.

Also there is no denying here that I'm overweight and I need to lose a lot of fat.

Thank's for your reply and I'll see you in Malaga Cove never ending climb.

Jenazah,

You already weighted yourself at casino point, so that's not the issue.

It sounds like you also have a lot of inherent buoyancy. Until you get rid of it, here is what you must do:

After your dive at malaga, leave your weights at the bottom. walk up with your tank, leave your tank at the top, come back down to get your weights. The more trips down, the faster the inherent buoyancy will go away.

Deep inside, you know I am suggesting a good thing here! if you have a good dive buddy, they will make the 2nd trip with you. Anytime you want to dive malaga I'll make both trips too! Everyone here can loose a few pounds, except for Melvin.

btw, dgallo, I think you are wrong, if he switched to a steel 80 tank, his total weight (tank + bcd + pouches) will be less.

hope this helps!
Scott

 

[dgallo]

Scott,

I have no doubt you may be right on this, but could you walk us all through it?

My mind says that if you need X amount of weight, then that's how much weight you need regardless of whether it is tank weight or on your weight belt. If you truly drop weight off of your belt, then you have less weight period. Shifting it around may improve trim, etc. - but it won't change your weight obligation, right?

EDIT: Never mind! I get it now!

I just went back and read the original post - I just noticed that he's wearing a two piece 7mm and not a one piece, so that explains some of the buoyancy issues.

 

[jenazah]

Perhaps I should also shave my head. Those hair is pretty bouyant too. Every little bit helps. But seriously thanks for all the advice. This is why I ask the question here instead of the general forums. You guys rock.

 

[pasley]

... Instead of losing weight, now I need 28 lbs. Because my new BC has a lot of inherent buoyancy and I added more wetsuit.

If you change nothing but go divining every week for about 80 or so dives a year, by this time next year you will be wearing 20 pounds of lead, or so, maybe less.
When I first started diving I wore 28 pounds of lead, AL80 tank, jacket BC and wetsuit. Now I dive 20 pounds, but have on occasion donated 4-8 pounds to a partner who could not get down. So I could get rid of some more I imagine.

The farmer john most likely accounts for the majority of the increase in weight. 1 pound of 7mm neoprene = 3 pounds of buoyancy

IMHO you are looking for an equipment solution to what is most likely an experience level problem.

I would just wait a bit and see how things settle in. Be certain when you are diving and trying to descend that you are moving absolutely nothing. I have often noticed myself and others unconsciously slowly fining while trying to descend. Just moving your hands around creates lift.

IMHO As a newer diver, now is not the time to be switching your gear around. Wait until you have more experience and have tried out some other gear and see what you like.

A simple, yet often overlooked point is that switching to a 6 pound back plate will remove 6 pounds of lead from your weight belt and change your trim. But it is still the same weight on your legs and to carry up and down the Malaga Cove hill. 6 Pounds of weight is still 6 pounds of weight, on you back or belt it makes no difference. Actually it does, ditch able weights can be ditched. What matters is what you weigh on the scales in full gear, because that is the weight you will have to schlep up the hill at the end.

 

[drbill]

Another factor may be the two piece 7mm suit you are using vs the one piece you were trained in. You now have 14mm over parts of your torso and some additional buoyancy until compressed. Not sure if it is enough to cause this. I haven't dived in a two piece suit in at least two decades, but I do dive with a hooded vest under my 7mm.

Dr. Bill

 

[scottfiji]

Scott,

I have no doubt you may be right on this, but could you walk us all through it?

My mind says that if you need X amount of weight, then that's how much weight you need regardless of whether it is tank weight or on your weight belt. If you truly drop weight off of your belt, then you have less weight period. Shifting it around may improve trim, etc. - but it won't change your weight obligation, right?

The whole "shifting weight around" thing is something I've heard discussed, but I guess I still don't quite understand the math. :06:

I just went back and read the original post - I just noticed that he's wearing a two piece 7mm and not a one piece, so that explains some of the buoyancy issue.

ok, I'll give it a shot -

You wear weight to compensate for the buoyance of the wet suit, tank , bcd, and yourself. Lets just focus on the tank in this example (we are also ignoring the tank valve):

weight carried up malaga cove hill = weight of tank + weight on belt (or in bcd) to compensate for buoyancy of an empty tank

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

for Catalina S-80, weight = 31.6 lbs (tank) + 4lbs extra on belt = 35.6 lbs carries up the hill

for a faber high-pressure steel 80, weight = 32.5 lbs (tank) - 7.3lbs less on the belt = 25.2 pounds carried up the hill

even if I have some things wrong, you can see that because of the buoyancy characteristics of an empty steel tank, you wear less weight on your belt, not more, for approximately the same weight tank...

hope this helps
Scott

 

[dgallo]

Okay so let me see if understand:

Catalina S80 = 31.6 lbs + 28 lbs weight belt
= 59.6 lbs up the hill

Faber HP 80 = 32.5 lbs + 21 lbs weight belt (subtract 7.2 lbs to adjust for buoyancy) = 53.3 lbs up the hill

Is that right?

I think I understand what you are saying now. That math totally makes sense to me. Thanks! I thought you were maybe doing some crazy math involving displacement!

- David

ok, I'll give it a shot -

You wear weight to compensate for the buoyance of the wet suit, tank , bcd, and yourself. Lets just focus on the tank in this example (we are also ignoring the tank valve):

weight carried up malaga cove hill = weight of tank + weight on belt (or in bcd) to compensate for buoyancy of an empty tank

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

for Catalina S-80, weight = 31.6 lbs (tank) + 4lbs extra on belt = 35.6 lbs carries up the hill

for a faber high-pressure steel 80, weight = 32.5 lbs (tank) - 7.3lbs less on the belt = 25.2 pounds carried up the hill

even if I have some things wrong, you can see that because of the buoyancy characteristics of an empty steel tank, you wear less weight on your belt, not more, for approximately the same weight tank...

hope this helps
Scott

 

[bob1dp]

If I am weighted perfectly for Casino I need 2 extra pounds to dive Malaga cove. I just spend more time shallower and the lack of compression makes me pretty darn buoyant. Also it takes about 2 pounds of lead to sink 10 pounds of fat. So if you dropped 20 pounds you’d carry 4 pounds less weight.

 

[jenazah]

OK here's the situation. During my class, I used 26 pounds with one piece suit and jacket BC from the class. I'm pretty sure I'm a bit overweight because when I deflate my BC, I just sink like a stone. Then I bought my own gear, 2 pieces suit and a back inflation BC. I stay with 26 pounds hoping that later perhaps I could drop a couple more. But I'm having trouble sinking and doing my safety stop with 500 psi left. I'm aware about the finning and shallow breathing and I really paid attention to that. Still I couldn't sink. I was fine with 28. Does 2 pieces suit really make that much of a difference ? It's a new suit also.

I think I'm gonna follow Pasley advice and just stick with my current gear. Although I probably going to buy Steel Tank since I need to buy another tank anyway.

Looks like for now, more diving and exercising should be no 1 & 2 on my agenda.

Thank's.