Lost 40lbs, need to change BP from SS to AL?

[Rooster59]

Can you jump in the pool with just yourself, no gear? Exhale, you sink, right? Full breath, do you float?

 

[NAM001]

Unless there is a plane taking me away in the next day,,, there is always a way to get in water. The poster is making too many changes at one time to have an easy way out of ding a proper weight check. The only thing you can do is compare the old weight to new. given that it is probably that no pool would allow a full rig n the water then he has to do the next best thing to get close before doing the actual check n the water he is diving. If he kept a log and noted what his #s were before the weight loss it would make it easier, but by omission of that info in the OP I have to go on the prospect that he did not log the info. My log has the weight needed for me in the suit only and me only. Had he had that info this would be elementary. clearly his weight loss did not affect his rig. so he can measure that. and then obtain the component of what he in his suit was.

In theory, yes, and in reality, some. But I suspect the area of neoprene covering your body is a much bigger factor in your diving buoyancy than your body composition. So, for example, if as a result of your weight loss you now use a Large wetsuit instead of a XXL wetsuit, that probably makes at least as great a difference as the loss of 20% body fat.

People seem to be overlooking the part of your original post where you said you "won't have the opportunity to do a weight check" before your trip. As you seem to understand, there is no way to get an accurate answer unless you do a weight check, by getting in water with your rig on, or weighing your rig by itself in a pool, etc. We're all just generalizing with our replies.

 

[Lorenzoid]

I still don't see how being a mere 4 lbs. heavier than one needs to be would be such an inconvenience for a 2-week liveaboard. There are divers who spend decades diving with 4 lbs. more than they could get away with but don't realize it or don't want to believe it or just don't care. If after a few dives you feel like you could shed some ballast, then by all means get the aluminum plate later. I understand the obsession with precision weighting--I do everything I can to avoid carrying 4 lbs. more than I need--but in the scheme of things it is not something I would fret over for purposes of enjoying an upcoming liveaboard. Just my thinking.