It's all a question of weight...

[nigelH]

Originally Posted by rustuk

Since beginning of Jan I've lost a stone and a half
I figured on maybe 2kgs off but is that too much?

The density of fat is 0.9Kg/L and muscle is 1.1Kg/L.

If your weight loss was just all fat loss your stone and a half, 21lbs say 10 Kgs, wins you a 1Kg loss of buoyancy. If you also traded in another half a stone, say 3Kgs, of fat for muscle that's another 600gms of lost buoyancy.

I'd go for removing one and a half kilos but it's a guess. One kilo is safe.

PS: Well done.

[andy pandy]

just out of intrest,

are you a member of mensa..........nigel

[chas49]

Originally Posted by Neil M

chas49,

surely decreasing fat, and increasing muscle will reduce, not increase the amount of lead required????

Cheers
Neil

oh bollox - i knew i was going to get it wrong I know what i meant though!!!

(just seen Nigel's post - which explains it excellently)

[rustuk]

Originally Posted by Neil M

Russ...

GIT
did you change your eating/drinking habbits as well??

Cheers
Neil

Sorry for being smug!!

Yes I did, but not that drastically, it was a case of eating less, but eating better. More fruit/veg, knocking out all the convenience and crap stuff, and (probably most importantly) no booze during the week...

[wilbo]

Originally Posted by andy pandy

just out of intrest,

are you a member of mensa..........nigel

He is a rocket scientist or physicist or something.. very bright chap..

[andy pandy]

Originally Posted by wilbo

He is a rocket scientist or physicist or something.. very bright chap..

Isnt he just.........Me im the scarecrow off the Whizard of Oz........




andy

[diver-repairs]

Originally Posted by rustuk

So I've had my smug gloat, the question is this...
I haven't done any UK diving yet this year (will be in the next couple of weeks) I dive a membrane drysuit, 15ltr & pony and carry 21 pounds (10 kgs?).
Do I need to drop the amount of weight I'm using (I figure I do) and by how much roughly?
Obviously the easiest thing to do is to buoyancy check when I jump in (and I'll do that anyway) but these dives will be boat dives and I don't want to (a) Sink like a stone carrying my usual weight or (b) float around on the surface because I've taken too much off.

I figured on maybe 2kgs off but is that too much?
Advice please?

Cheers
Russ.

Russ, get your gear and get in some fresh water at the pool or any old quarry and do a bouyancy check, pick up or drop weight till you are completely neutral with your main tank down at 50 bar.

Then do the calcwith your TOTAL /all up weight add on the 3% to your weight belt and you won't be far out when you jump into sea water off the boat....If I've got it wrong send your widow to sue me...

hth

Brian...congrats on the weight loss anyway...

[Neil M]

Originally Posted by rustuk

Sorry for being smug!!

Yes I did, but not that drastically, it was a case of eating less, but eating better. More fruit/veg, knocking out all the convenience and crap stuff, and (probably most importantly) no booze during the week...

Trying all that! and 3 boxercise classes a week and 3 or more gym sessions.... oh well must try harder! (well actually, I'll be cycling to work again soon)

I think that cutting out the booze is one of the best steps......

[Okeanos]

Either do what Nigel says or do nothing, an extra kilo will not cause you to sink to the bottom uncontrollably, you have buoyancy control devices for that.

There is no hard and fast calculation, Nigels is good, but its all down to body volume displacement. Loosing fat and gaining muscle doesn't necessarily mean you would have changed total body volume. It takes cells ages to shrink after losing some fat content, yet muscle will grow quickly back to it previous maximum size. You could actually displace more water and not need to lose any weights at all.

A buoyancy check is the only real test.

[SCUBA_G]

Fair play, Im still trying to lose the extra few togs of flab myself. Being a membrane suit, I assume it will be slighty loser than before, so a little more air than before, once youve made sure thats out, Id say you might drop about 2kgs max, the way Id do it is drop the lead from your belt and have 2 1kg weights with a cable tie and snap hook, hit the water, do a buoyancy check, if you need more lead, hook it on, this I find an easy way to adjust without messing about for long, then after wards make the permanent adjust then?