enough weight

[rtreefanatic]

my girlfriend is trying to get certified but is having a problem with bouyancy. she lets all the air out of the bc but still has issues getting down and staying down. the instructor says 10# is enough and that she doesn't need any more weight and won't allow any more, that she is the problem.
question: aren't some people just naturaly more bouyant than others?
and shouldn't instructors be a little more flexible with this?
isn't it better to be slightly negative than to be positive at the start of a dive due to aluminum tanks being positve at the end of the dive?

 

[TMHeimer]

Puzzling. The weight check was done? Yes, people can vary greatly in natural buoyancy. If the weight check was done, it's not a matter of an instructor being more or less flexible (it is what it is). After the weight check, 5 lbs. should be added as the tank gets lighter as air is used up (whether aluminum or steel-doesn't matter)--therefore you are 5 lbs. negative anyway at the start. Could there be any other reason he says no more than 10 lbs.?

 

[rtreefanatic]

says 10# is enough. i had 8# on her in a pool with no gear and she was barely staying down. i know bouyancy gets better with more experience and relaxation so this is puzzling me as to why she just isn't allowed to add a few # so she can continue with her training( now she's starting to stress about it which is detrimental). i know many people who need more than 10 #. i even stated with more than that but have progressed to less than 8# w/ al 80 and a 3mil suit, but it took a while.
i don't know what to but just tell her to listen to the instructor because i will not contradict him, he is the instructor and she needs to listen to him.

 

[Akimbo]

Archimedes Principal appears to be quantitatively proving your girlfriend's instructor wrong. Has she found how much weight she needs to reach neutral buoyancy without a BC or Scuba gear?

Perhaps this will help:

http://www.scubaboard.com/forums/basic-scuba-discussions/344735-minimum-diving-weight.html

In case they did not teach her Archimedes Principal:

Archimedes' principle

 

[Erku]

i don't know what to but just tell her to listen to the instructor because i will not contradict him, he is the instructor and she needs to listen to him.

I'm as green as she is, but what I've been hearing on the boards is that noobs like us need to be a bit careful about this philosophy. If her buoyancy check doesn't get her floating at eye level with an empty BCD and full lungs, she needs more weight and that's the end of it no matter what the instructor says. Even if it does turn out she still needs the extra 2kg/5# to account for an empty tank. If she's doing PADI it's right in the manual.

If the buoyancy check came out right at around 5# and the instructor added another 5# he has a leg to stand on, but if not it sounds like he's being stubborn, and ruining her dive experience as a result.

Could you help her smuggle in some of your own weights to slip in her BC pockets or something?

 

[Dave1981]

If the instructor is saying no more weight then chances are you have a good instructor trying to not allow the common practice of overweighting divers to make the course easier.

A natural reflex is to not fully exhale when you go underwater.. without scuba gear it'd be a bit silly right? Another one is to unknowingly kick up as you try to descend. Some take a breath as soon as they submerse. If the instructor has spotted any of these then the patients to do it right from the outset will be worth it in the end. It's easier to instil good habits from the start than break bad habits later.

 

[Erku]

If the instructor is saying no more weight then chances are you have a good instructor trying to not allow the common practice of overweighting divers to make the course easier.

A natural reflex is to not fully exhale when you go underwater.. without scuba gear it'd be a bit silly right? Another one is to unknowingly kick up as you try to descend. Some take a breath as soon as they submerse. If the instructor has spotted any of these then the patients to do it right from the outset will be worth it in the end. It's easier to instil good habits from the start than break bad habits later.

If she's getting this stressed about her dives, I'd question whether the instructor has approached the situation in this manner. You could easily be right, but without teaching her to overcome these habits and get into negative buoyancy territory I'd say it definitively isn't good instructive habit, no matter how noble the goal is. Of course we're both labouring under second hand information and assumptions made from it but she cain't larn what she ain't been taught, so to speak.

 

[scubafanatic]

Your instructor is a idiot! It's better to risk being a little overweighted than underweighted, as an uncontrolled ascent can be fatal! And 'no', you shouldn't have to smuggle secret weights in the BC pockets! It's perfectly OK to be a bit overweighted, get some dives in, and simply do dive #1, see how it goes, then on dive #2, remove 1 or 2 lbs of weight, see how that goes, do dive #3, remove 1 or 2 lbs of weight, see how that goes.....see the pattern here ? There's NO WAY anyone can flat out say '10 lbs is enough' especially as weighting varies depending on if you're diving fresh vs salt water....wetsuit thinkness.....tank type/size...etc! Pissing off a new diver right off the bat over someting as silly as this really takes the cake!

 

[TSandM]

New divers often have problems descending, and it is very tempting to keep adding weight until their improper technique is simply overriden by gravity. Now, it may be that your GF needs more weight; but it may also be true that she simply needs some good instruction on how to descend. What NW Grateful Diver taught me, when I was new, was that the usual instruction to hold the inflator hose up, vent the BC and exhale, doesn't work very well. If you exhale when you are still well out of the water, then about the time your head goes under, you need to inhale again, and you rise. Instead, start to vent the BC and INHALE. As your head reaches the water, exhale sharply and hold it -- you will continue downwards.

In addition, many people fin constantly while at the surface. This can, in part, be due to poorly balanced equipment that is trying to pull or push you over, but it can also just be lack of relaxation and comfort in the water. At any rate, if you vent your BC and continue to kick, you won't sink very well. Again, Bob taught me to cross my ankles to prevent doing this, and if you bend your knees at the same time, you will effortlessly rotate into a horizontal position as well.

I would try some of these ideas before I packed more weight on -- but doing a formal weight check is the first step.

 

[rtreefanatic]

she's having difficulty staying down once she's on the submersed platform. and i agree with the noob issue of not exhaling completely. but once she's down and not finning and bc empty she is still having a tendency to rise. seems she'sust naturally bouyant.
i do not want to see her waist her money on having to retake classes or take months to get certified.
if she brings up the idea of more weight from what i'm told she gets corrected immediately. i don't what to do as i do not attend these with her. i know the instructor is a good teacher but maybe there needs to be some flexibility i don't know, i was taught to listen to the instructor.