Buoyancy and weight loss...

[svnipp]

Another noob question here... I don't even take my OW class until next month, so please be gentle on me.

Obviously I'm soon to take up diving and buoyancy seems to be one of the tougher and critical skills to master. Add to this that I'm hoping to lose about 40 lbs. prior to death, seems I'm always trying to lose somewhere between 30 and 50 lbs. Assuming that I am successful and keep my weight on a steadily downward trend I'm guessing that I am always going to be mucking around with my weighting, right? Or does 5 to 10 lbs of body weight for a ~ 250 lbs guy make that much difference to my natural buoyancy?

Thanks as always for the great info.

 

[vladimir]

A liter of fat weighs ~.9 kilograms and, by definition, displaces 1 kilogram of fresh water, so for every 10 kilos you lose you can take a kilo off your weightbelt.

 

[Mike Boswell]

I was in the same position when I started my OW class two years ago. I lost 50 lbs (on Atkins) and was able to take 4 or 5 lbs of lead off my weight belt. I think the general rule of thumb is that you can remove 1 lb of lead for every 10 lbs of fat you lose.

The only problem was, after I lost the weight I needed a smaller BCD.

 

[redacted]

A 2 to 4 % change in body weight is mostly negligible except as it effects the amount of neoprene you wear which may have a noticeable effect. Body fat will effect the amount of weight you require such that folks like you and I probably need 6 to 8 pounds of neg buoyancy just to get our FAs to sink in SW while those with close to zero body fat may require little to no lead. But with fat density around .9, 10 pounds of fat only takes about one pound of lead to offset it. When you lose that 40 pounds, you should be able to drop 4 lb from your belt plus whatever you get to drop (or add) due to the new set of neoprene you will need.

 

[NC Wreck Diver]

These posts are accurate. Good luck on the weight loss. I did it on a low carb diet too, and took 60# over 6-7 months. I did take off a good amount of SCUBA lead. The last 10#'s of body weight are the toughest, but don't get discourged. Stick with your program. You will be surprised how much better you feel! When you hit your goal weight, lift up something that weighs around the amount you lost. Think about that weight. This is the extra weight that you lifted, just getting up, etc. Good Luck!

 

[svnipp]

I was in the same position when I started my OW class two years ago. I lost 50 lbs (on Atkins) and was able to take 4 or 5 lbs of lead off my weight belt. I think the general rule of thumb is that you can remove 1 lb of lead for every 10 lbs of fat you lose.

The only problem was, after I lost the weight I needed a smaller BCD.

Thanks for all the encouraging words. Although I need to drop 40+ lbs, my weight is pretty well distributed, and my gut isn't just a whole lot wider than my shoulders so I'm hoping that I may not need to replace a wetsuit. I figure I can squeeze into an XL now, and should be OK in that if I can ever get all the weight I want to lose off. If not, I'm willing to invest in a new wetsuit as a reward for the weight loss.

I'm really pretty sure though that I won't need to replace my BCD though. I'm pretty broad shouldered as mentioned above and that isn't going to change with my weight loss.

 

[Akimbo]

The specific gravity of fat issue has already been explained but there is another variable. In the process of loosing weight and becoming an active diver you are likely to gain some muscle mass, increase lung capacity, and reduce the surface area of your wetsuit — I am guessing wetsuit rather than drysuit diving in the Gulf off Texas.

From the cost standpoint, a little lead one way or another is not big deal. Replacing your wetsuit is more likely to get your attention, but is no reason not to loose weight. In fact, you should buy the most expensive custom wetsuit available once you get down to your target weigh. It will be an incentive to maintain your weight!

 

[NC Wreck Diver]

Dude:

Think about changing your thought process. You CAN take the 40 pounds off (not hope). If I can take off 60 pounds off at 49 years old, you can easily make the 40 happen. It's the same discpline that you use for diving. You want to do it, so just do it.

So, without sounding like a TV commercial for weight loss, set your goal, and stick to it. When people start to comment about how much better you look, it is really the best reinforcement you will experience.

Thanks for all the encouraging words. Although I need to drop 40+ lbs, my weight is pretty well distributed, and my gut isn't just a whole lot wider than my shoulders so I'm hoping that I may not need to replace a wetsuit. I figure I can squeeze into an XL now, and should be OK in that if I can ever get all the weight I want to lose off. If not, I'm willing to invest in a new wetsuit as a reward for the weight loss.

I'm really pretty sure though that I won't need to replace my BCD though. I'm pretty broad shouldered as mentioned above and that isn't going to change with my weight loss.

 

[drdaddy]

When I lost 10 pounds I also took 5 pounds off of my weight belt. This took a total of 15 pounds off of my knees when I climb over the rocks of the jetty - I could really feel it. Also, it was not just "10 pounds of fat" that I took off - maybe it was 15 pounds of fat (which floats) and put on 5 pounds of muscle which sinks. Regardless, it was a good thing to do and 5 years later I have kept that 10 pounds off and fluctuated in the next 10 pounds. (Probably has something to do with that carrot cake with cream cheese frosting that just melted in my mouth minutes ago.)

Anyway, fat loss and muscle gain really do affect your buoyancy.

 

[Mike Boswell]

Thanks for all the encouraging words. Although I need to drop 40+ lbs, my weight is pretty well distributed, and my gut isn't just a whole lot wider than my shoulders so I'm hoping that I may not need to replace a wetsuit. I figure I can squeeze into an XL now, and should be OK in that if I can ever get all the weight I want to lose off. If not, I'm willing to invest in a new wetsuit as a reward for the weight loss.

I'm really pretty sure though that I won't need to replace my BCD though. I'm pretty broad shouldered as mentioned above and that isn't going to change with my weight loss.

You might be okay. At 240 lbs I wore a Seaquest Balance XL BCD but when I lost 50 lbs the BCD was loose with all the straps as tight as they could go. I was looking at new BCDs ($700) when I discovered the Backplate/Wing system, which can be bought new for $400 or so and fits anyone at any size or weight.

Now, I need to buy a new wetsuit.