Big deal about amount of weight?

[stuartv]

I'm in the process of getting my OW cert. I had all the confined water work over this past weekend in a local pool.

I am 6' 1", 230 #. I was wearing a 3/2 full suit with the typical rec-style BCD (whatever the shop issued me for the class).

On Sat, I ended up with 8 # of weight in my BC. I could descend. My problem with it was that it was trying to flip me on to my face. The instructors told me I need a "back inflate" BC so that we could put some trim weights in pockets on the back. But, they didn't have any in my size there with them at the pool, so they said they would bring one for me to use on Sun. In the meantime, I just dealt with it.

On Sun, I had a new BC that they had added a couple of trim weight pockets to, by hanging them on the tank band. I started with 4 x 2 # weights - 2 in the 2 front pockets and 2 in the 2 trim weight pockets on the back. There was still a bit of tendency to flip me on my face, when on the surface. Eventually, an instructor added 2 more pounds of weight.

Later on Sat, I was talking to an instructor about my rig trying to flip me on my face and he asked me how much weight I was using. He seemed shocked when I told him 8 # and said that was awesome. Again, on Sun, a different instructor (the one who added my 2#) asked me how much weight I was carrying and I told him now 10 #. He said when I go to the Caribbean and I'm in salt water, I should start with 14 # and that that is awesome that I am using so little weight.

So my question is, why is it "awesome" that I'm 8 or 10 # of weight in fresh water or 14 # in salt water? It seems like whatever it takes for me to achieve the right buoyancy is what it takes. But, the way they talked about it, it was as if there is some skill associated with needing less weight and I was showing excellent "skill" for being a newb. Which is what I don't understand. How is there skill in being a certain overall density?

And while I'm asking questions, why did they tell me I need a "back inflate"? I assume that's referring to a BCD that just has the air bladder on the back, versus a jacket style that also has part of the air bladder wrapping around the diver's sides, towards the front of the body?

It seemed that I needed to add some trim weights on my back. So, why would being a back inflate be a prerequisite for doing that? It seems like any style of BCD could have trim weight pockets on the back. And any that didn't have those could have them added on the tank band.

Thanks in advance for clarifying any of this.

 

[DivemasterDennis]

It's about trim, or body position for you, not just the amount of weight. If you have to keep air in your bcd, it will affect your trim. It may be the case that you are a little OVERWEIGHTED, With air in the bcd pushing you around. A Back inflate will be worse, not better, than the jacket style in causing this effect. You body type, not just height and weight, impact proper weighting. I would experiment with a little less weight and see if that does not improve your body control. And don't ignore other factors: tank type and size and position, and other gear worn.
DivemasterDennis

 

[stuartv]

It's about trim, or body position for you, not just the amount of weight. If you have to keep air in your bcd, it will affect your trim. It may be the case that you are a little OVERWEIGHTED, With air in the bcd pushing you around. A Back inflate will be worse, not better, than the jacket style in causing this effect. You body type, not just height and weight, impact proper weighting. I would experiment with a little less weight and see if that does not improve your body control. And don't ignore other factors: tank type and size and position, and other gear worn.
DivemasterDennis

So you think with 8 # of weight, I might have been overweighted?

---------- Post added October 27th, 2014 at 10:29 AM ----------

Anyway, again, the question is why would the dive instructors think it's "awesome" that I would be good to go with only 8 or 10 # of weight (in a pool, wearing a 3/2 wetsuit)? Why is needing less weight "awesome"? It seems like the amount of weight would be just whatever it is - no reason to be impressed by a low number.

Or, what does needing less weight really say about a diver, such that lower numbers would be considered "awesome"? All I can come up with is that needing less weights means I'm more dense. And, while being dense may be a characteristic of mine, it's definitely no skill. ;-)

---------- Post added October 27th, 2014 at 10:31 AM ----------

don't ignore other factors: tank type and size and position, and other gear worn.
DivemasterDennis

I think we were using AL80s. Am I correct in thinking that having the tank too low on my back would tend to push me face forward when floating on the surface?

 

[Wookie]

He said "awesome" because most new divers are put in 12# for girls, 16# for boys automatically by their dive instructors. Newer divers tend to hold their breath more than divers with a few dives under their belts. Holding their breath makes them more buoyant, so they *need* more lead. Or they need to be taught to relax, although OW mill schools don't take the time to do that. Now, we need to work on your trim. Is the complaint that you are being flipped on your face underwater or at the surface?

I think it's awesome you are in 8 or 10# too. It says to me that you are relaxed in the water and ready for anything. Good on ya.

 

[tbone1004]

agreed, can you define flipping you on your face though? You want all of the weight to be below your body, at the surface it will tend to pull you forward, but you want that under water, if you put the weight on the cam bands in the back it will cause you to roll over on your back, which is real bad....

 

[Wookie]

He said "awesome" because most new divers are put in 12# for girls, 16# for boys automatically by their dive instructors. Newer divers tend to hold their breath more than divers with a few dives under their belts. Holding their breath makes them more buoyant, so they *need* more lead. Or they need to be taught to relax, although OW mill schools don't take the time to do that. Now, we need to work on your trim. Is the complaint that you are being flipped on your face underwater or at the surface?

I think it's awesome you are in 8 or 10# too. It says to me that you are relaxed in the water and ready for anything. Good on ya.

Now. As soon as OW class is over, find someone who will work with you on trim. It can be done in the pool, it doesn't need to be in the lake. Some old curmudgeon like me will spend hours with you fitting you into different BCs/buoyancy systems, moving your weights around, moving your tank higher or lower, etc. I love doing that with folks, way better than teaching OW.

 

[drbill]

Eight pounds of weight? With a 3/2mm wetsuit I dive with 25# so you are doing quite well. However, as others have pointed out your trim is affected by where that weight is placed. I put all mine around my biggest floatation device... my belly!

 

[stuartv]

My main trouble was on Sat and it was trying to flip me on my face when I was on the surface. A couple of the other guys were having the same problem. Everyone else (women and teenagers) all seemed to float on the surface with no trouble.

On Sun, with the weight moved around so I had 2 # in each front pocket and 2 # in each back trim weight pocket, the push to flip me on my face was still there just a bit, but much better. However, with the weight on back, I did have some issues with my rig trolling to roll me to the right when I was underwater and horizontal. That is when my instructor bumped me from 8 # to 10 # and shifted some stuff around. He added weight by adding 2 # to my left front pocket. So then my rig wanted to roll me to the left even harder. Then he shifted my left rear weight around to the back center of the tank band and I was pretty much okay after that.

All in all, I thought the way the shop/instructors dealt with my buoyancy issues was not that great and not very educational. But, at least I was able to complete the pool work with no significant problems. Now, on to the quarry this coming weekend to knock out the open water dives. Yay!

Wookie, thanks for the explanation.

 

[Wookie]

All in all, I thought the way the shop/instructors dealt with my buoyancy issues was not that great and not very educational. But, at least I was able to complete the pool work with no significant problems. Now, on to the quarry this coming weekend to knock out the open water dives. Yay!

Wookie, thanks for the explanation.

It's a time issue. I don't know how many were in your class, but the pool might have been rented for someone after your class was out of it, or the instructor had another engagement. They have a finite amount of time to run you through the process, and the fine tuning comes when you have your own gear anyway.

Look at this another way. Driver's ed in high school didn't teach you to drive, either your dad did that, or you are intuitive. Driver's ed taught you to pass the driving test. Same with scuba class. They aren't teaching you to dive, they are teaching you the fundamentals of not killing yourself in the water. You wouldn't drive a grand prix right out of driver's ed, and you aren't going to be ready for a 300 foot solo rebreather dive next week, either.

Don't be too harsh on your instructors. Sounds like they got you trim enough to be comfortable in rental gear, to get through a class, and to be safe enough to go plan your own dive. The fine tuning comes with time and experience. I can't tell you (I guess I could) how much dive gear I've bought and used once, stacking it in the corner and buying something else. Take your time, go slow, and learn something on every dive.

 

[AdivingBel]

Could be too much air in the wing/jacket BC bladder. My wife had the same issue during her OW. Some instructors/DMs are more concerned with new divers floating when they first hit the water. Since new divers are often overweighted in order to get them under and they may be apprehensive about hitting the water with all the "new" gear and lead weight, many times the BCs are overinflated to initially hold them on the surface. This can cause bobbing on the surface like a cork without control. It can also cause an uncomfortable "squeeze." You want just enough air to float your head comfortably out of the water. It's can be tough for a 3rd party to judge how much air is in the bladder and they error on the "too much" side. With practice new divers learn to judge for themselves and they become comfy with their head going under water upon entry, knowing they'll pop right back up. Good luck.