Buoyancy

[DM_cappie]

I agree with DivemasterDennis, add a pound if it makes you breath more comfortable, but it sounds like for pool exercises you were pretty close to perfect....
when you move on to open water though, I would add some more weight, normally I plan my weight to be prepared for a safety stop with a empty tank....another thing to consider (and I appologize if I missed someone nemtioning it already) assuming you do your open water dives in salt water , your going to have to adjust to that too

 

[DukeAMO]

Of course, you'll have to figure this out again when you get to your checkout dives, when you'll probably be wearing different exposure protection, and possibly diving in salt water! I had to add an extra 6 lbs myself, just because we went from wearing shorties to wearing 2 5mm wetsuits at once.

I'm no expert on this yet, but I do have a funny story -- in our OW dives, I was subconsciously "breathing off the top" a bit. Whenever I got really interested in a fish or something, I'd relax and let a breath all of the way out - and start to sink! And then once you start to sink, you accelerate down unless you add air to our BCD (especially at around 20ft, which is where we spent most of our OW dives). You end up having to play around with the BCD a lot when you're new.

Also, if you're lucky, once you get past the first couple of OW dives (where you have to take off your weights several times), you'll be able to integrate the weights into your BC (assuming it has a weight integration system). That makes life easier, when your hips aren't being pulled down as much.

 

[Crewfish13]

I agree with DivemasterDennis, add a pound if it makes you breath more comfortable, but it sounds like for pool exercises you were pretty close to perfect....

I'll third this one. I was weighted similarly in my pool sessions, and my instructor did a very good job in our first pool session or two in pointing out to me when I was breathing off the top. Basically, I could kneel on the bottom breathing deeply, and if I took a deep breath or didn't exhale completely, my knees left the pool floor. I tended to have trouble donning the BCD underwater, and when I got frustrated, I'd start floating. By the last half of my pool training, I could actually use this to realize when I was getting anxious and remind myself to calm down. A couple slow, deep breaths later, I was back with my knees on the bottom and a clear head, ready to resume the exercise.

 

[TMHeimer]

+1 on DDennis' about adding a pound or so. Lots of good advice, particularly about the difficulties in shallow water. Question--did you do a proper weight check in the pool (even with full tank) to determine you needed 8 pounds? We have only 8 and 12 pound lead shot belts for the pool (so no bottom damage when dropping them). At ocean checkout dives, no weight checks are done due to the fact that the water here is often 35-40 F with students in wetsuits--can't add extra time in the ocean for that. So weighting is far from perfect. As an OW student I was up & down all the time and immediately improved greatly when properly weighted with my own gear. Even as shallow as 2 feet from the surface I began to feel like a pro. If properly weighted you still may have more initial problems with those big lungs, but I don't THINK shooting up & down fast would happen. Of course, everyone is different.

 

[GROBIOG]

Isn't adding more weight going to require more lift? More lift means either kicking upwards or more air in the bladder(BCD), the air volume in the lungs is still the same.
Typical dive industry bs, trying to fix issues with more equipment rather than improve skill, and in this case an issue that doesn't exist.
The op has very damn good understanding of what is going on, this is huge, has not even finished class yet, buoyancy is by far one of the hardest things to master in scuba and it sounds like you're in the right path.
Practice and more practice is the best thing you can do, sounds like you just need to work on your breathing(will improve naturally with more dives under your belt), trim is also a very underestimated part of it, trim is actually just as important as neutral buoyancy.

 

[Tigerman]

Yes, more weight means more lift to compensate for it is required, but a guy with big lungs can offset that pound quite easilly only by breathing

 

[GROBIOG]

Yes, more weight means more lift to compensate for it is required, but a guy with big lungs can offset that pound quite easilly only by breathing

So now he has to take a bigger breath because you just overweighted him.
Read his post again, when hi's breathing is normal he has NO issue staying neutral

 

[Tigerman]

I wasnt the one suggesting adding weight, I merely replied to the physics..
However, if he WAS weighted properly, but with a full tank rather than an empty one hes actually a bit underweighted and might find that hes a bit light for a SI with an empty tank, which is probably why people suggested adding a pound.
That said, the pool work might be done in different wetsuits and salinity than the OW dives will, so he might to do a new weight check for his ow dives anyways.

 

[dumpsterDiver]

Hello All, I completed class #2 of my PADI OWD course and have a question about my Buoyancy. I am a big framed guy that is 6 foot 5 inches 260lbs. We are currently pool diving with shorty wet suits and I am using 8 lbs of weight. Now, if I take a full deep breath and fill up my lungs, up to the top I go or I am not able to sink to the bottom without making sure my lungs are just about empty. In your opinion, do you think I need more weight or as I have read do I just need to learn to control my breathing a bit more? I was able to keep to the bottom of the pool by breathing correctly with no issues so it would seem that I am properly weighed. Just seeing if anyone had any additional thoughts.

Thanks a bunch and this is a really cool thing to be diving so far, Love It!!!

Not being able to sink until his lungs are almost empty is a clear sign to me that he is underweighted. It is a sucky feeling to not be able to really breath because you start floating up. It's like a constrictor snake is on your chest and you can't really inhale.... this is not the way to dive, plus if that is happening in the beginning of the pool session, it is going to be a real problem toward the end when the tank weighs less.

It would not be at all unusual for someone that size in a shory to need 10 or 12 lbs for the pool. I would add 2-3 lbs and try again, even if you add 5 lbs and are a little over weighted, it only takes a fart in the BC to counter act 2 lbs or something. PLUS... the guy is never gonna learn to use the BC if he never puts any air in the damn thing when he is underwater in the pool.

 

[Mr. Green]

All, Lots of good advice and I Thank You all. In the next couple of pool sessions I am going to mess around with my weight and see how it goes. I am leaning lots of good tips from the board that can help me out going forward. I will keep you all updated in the next week or so.