OW - Float at eye level?

[Hank49]

Most all students start out NEEDing more weight though. Probably due to hyper breathing causing more buoyancy. As they relax they can start decreasing weight.

 

[soonerwink]

I do a weight check with my students at the beginning of every pool session and at the end on the last three. Overweighting students is poor practice. It only enforces bad habits. And if you do not do skills planted on the bottom but hovering and horizontal in the pool it shows when they get to checkouts. They naturally drop down the line and at 5-10 feet get horizontal the rest of the way to the platform. Stop a few feet above it, get stable, and then we do skills. Overweighting would result in them having excess air in the bc to remain neutral or force them onto the platform. That excess air due to overweighting could result in a runaway ascent if they freak and don't dump fast enough on the way up. The pool is exactly where proper weighting should begin and from day one on scuba.

I am just quoting what an instructor told me, when I asked him why the students were wearing so much weight. I would say that none of the instructors I have worked with were lazy or cut corners. I don't think that is a fair statement, just because they don't teach the way you think they should.

 

[Al Mialkovsky]

Having to kick down to descend, and only being neutral at 8-10 ft, would just be cutting it too close for me.

I've never ended up on the surface without wanting to be there and I've never had an issue because of my weighting technique. It's not how I weighted students and not how I weight myself while teaching but it's worked great for my personal dives and it's what I've always told students to do later on. SAC rates improve a lot when you aren't fighting being over weighted but most divers and most instructors wear a lot more weight than they need.

 

[bestyman]

Thanks for all the replies. It sort of makes sense that he wanted to keep us att the bottom as that week we were doing reg removal, mask clearing etc.
I have always thought of him as a very good DI, so hopefully he will move on to bouyany control in later weeks.

Jim Lapenta said " That excess air due to overweighting could result in a runaway ascent if they freak and don't dump fast enough on the way up."
Other than that reason what are there any other issues with having too much weight? As long as you go up and down makes sense to me , or am I over simplifying things?
Also , what is a SAC rate?

 

[ZenDiver.3D]

Most instructors I have worked with like for their students to be over-weighted while doing skills on the bottom of the pool and the lake. It helps to keep them stable on the bottom while performing the skills that are required. He still should have given you an explanation, instead of telling you just to ignore it.

I always hate this. Many instructors like their students to be overweighted. IMO this is flat out laziness on the instructor's part. Don't sugar-coat it by saying it helps stability on the bottom. Why do you need to be stable on teh bottom? Who dives crawling along the bottom? (can you tell this is a pet peeve of mine?) They should be teaching their students proper bouyancy techniques and control at the outset and they wouldn't need to turn their students into rocks. I'm not fussing at you, Soonerwinks, but at this excuse that instructors like to use . There is not a good explanation for overweighting a student ever.

Most all students start out NEEDing more weight though. Probably due to hyper breathing causing more buoyancy. As they relax they can start decreasing weight.

Mine don't. I start them in the shallow end of the pool with no wieght, floating face down on teh surface. I have already had them practice breathing properly and working on breath control skills for bouyancy above water. We lay there and breathe. And try to see if any can get themselves to sink. We then add small amounts of weight slowly until they can sink and stay down. Then I have them add a small amount of air (fin pivot...), then learn to hover. They then work on moving up and down in a hover right there. First class. Before mask clearing underwater. They have already cleared their masks above water and with snorkles on anyway.

I have just properly weighted each diver. Not overweighted. My students Never perform a skill kneeling or on the bottom. They hover. They are allowed to reach one finger down to touch the bottom as a guide when they are preforming skills to keep track of their placement. And Thus, they never touch bottom in pool or sea. They learn to descend and hover at horizontal. It takes more time and work on the instructor's part. Most don't do that. I wish we all did.

My OW 1 and 2 students this weekend went with another dive group and us on the same boat. Their students descended and stood on teh bottom to do their skills. Mine descended, hovered, did the same skills, and then we left to tour the reef. The others were shocked. I think it's sad.

I am just quoting what an instructor told me, when I asked him why the students were wearing so much weight. I would say that none of the instructors I have worked with were lazy or cut corners. I don't think that is a fair statement, just because they don't teach the way you think they should.

If they made their students into rocks, they were.

Thanks for all the replies. It sort of makes sense that he wanted to keep us att the bottom as that week we were doing reg removal, mask clearing etc.
I have always thought of him as a very good DI, so hopefully he will move on to bouyany control in later weeks.

Jim Lapenta said " That excess air due to overweighting could result in a runaway ascent if they freak and don't dump fast enough on the way up."
Other than that reason what are there any other issues with having too much weight? As long as you go up and down makes sense to me , or am I over simplifying things?
Also , what is a SAC rate?

Because you will not learn proper bouyancy control if you are overweighted. Because you will use more air and thus shorten a dive significantly if you are overweighted. Because you have to hold too much air in your bc to become neutral and thus can have triouble on ascent, like Jim said.

To answer the original question- With a full breath of air and an empty bc, you should bob at the surface. Most won't be right at eye level, but the key is that you should not be able to descend. As you release your breath, you should sink slowly like a feather. Not a rock.

Most instructors teach the way they were taught to teach. And most will consistently overweight. It is faster and easier to maintain the herd. But that doesn't make it the right way. The right way takes more time and energy, requires smaller class sizes, and more training sessions. To me "good enough for a new diver" - isn't.

 

[Al Mialkovsky]

SAC rate is sufrace air consumption rate which just means how much air you use. There is a formula that you may learn during open water classes. After you get some experience just start trying lower weights, keep your arms from flapping and do steady relaxed fining and you'll be surprised how much better you breathe.

 

[TSandM]

bestyman, the big issues with being overweighted are these: When you are carrying too much weight, in order to get neutral to swim, you have to put too much gas into your BC. A big air bubble in the BC is pretty unstable -- it will shift from side to side and tend to increase your likelihood of turning turtle. It will expand quickly as you rise, and make it more difficult to avoid unintended ascents. It can even make your BC uncomfortable to swim in, as it may become tight around you. Proper weighting makes a dive much more pleasant and a bit easier, and this results in a diver being able to relax better. When you are relaxed, your breathing is slower and more rhythmic, and you don't use up your air as fast.

It IS pretty common practice to do skills on your knees, especially at the beginning of a class. And it's HARD to sit on your knees if you are perfectly weighted, because you only "weigh" about three or four pounds (the weight of the gas in your tank). So any movement will push you up off the bottom and into the water column, which is, of course, what you WANT when you are really diving. But for your first pool session, it can be a little easier if you're a bit more firmly planted.

Another issue can be equipment. The shop Peter used to teach for uses steel rental tanks, because aluminum is not as good a choice for our cold, salt water. But if students come to the pool in bathing suits, they may not have enough personal buoyancy to offset the negative tanks, so they may not be able to be neutral at the surface.

At any rate, I agree that you should have been given a better explanation than you were. Certainly, if there are any other questions you have, where you don't feel as though you got a good answer, please come here and ask them. Understanding what you are doing will make you a safer diver.

 

[Walter]

My DI

You have a drill instructor? That sounds like a tough class.

if at the end of the dive you don't propertly vent your BC you'll likely rise to the surface when you get shallow.

Why would you not properly vent your BC?

Being weighted as I do also makes buoyancy pretty easy to achieve.

If you're diving in just a swim suit, that works well. If you're wearing a wetsuit, it makes it difficult to ascend slowly from your safety stop. SCUBA divers should be neutral at the surface.

 

[Peter Guy]

Bestyman -- Thank you for your question about the difference between what your instructor said and what was "in the book." I know that at times there may be a difference between "reality" and "the book" and it may not mean anything more than "the book" can't cover all possibilities. It, for sure, does NOT mean your "instructor is an ass" which is something that should NOT have been written!

Back to your question -- At this point, quite frankly, none of us know if you were, in fact, overweighted (although you may have been). It really depends on the gear you were using. My students, for example, will generally find it impossible to do a "Proper PADI Weight Check" in the pool using the gear the shop provides. It is NOT because I want them "planted on the bottom" but, to the contrary, because the tanks are negative AND the tanks are full AND the students need to be wearing a weight belt for the practice (only 4 pounds but....) AND the students don't wear any exposure protection.

When you add that all up, most people are quite negative at the start of the dive and there is no way they can "float at eye level with an empty BC and normal lung volume". It just can't happen.

One of the big problems with the "PADI Weight Check" is that it is done at the start of the dive when your tank is full and you are at least 5 pounds "overweighted" -- but you are NOT "overweighted" just negative. That is partially WHY we have Buoyancy Control Devices (that and suit compression). IF you did the weight check in the pool, at the start of the dive, with a steel tank and without any wetsuit, YOU SHOULD BE NEGATIVE and sink like a stone with a totally empty BC.

The only criticism I would have of your instructor is that he didn't explain that -- but, at the same time, I can understand it. He had limited pool time and probably other students. This is one of those things that you should ask at the next class session.

Me, I'm giving the instructor the benefit of the doubt regarding weighting, for in the pool in many circumstances, "The Book" doesn't work!

 

[Al Mialkovsky]

Why would you not properly vent your BC?

Because new divers quite often don't as I'm certain you've noticed

If you're diving in just a swim suit, that works well. If you're wearing a wetsuit, it makes it difficult to ascend slowly from your safety stop. SCUBA divers should be neutral at the surface.

I don't get your point, there is a correct amount of lead based on whatever you happen to be wearing from swimsuit through dry suit.

Funny how what works great for me isn't good enough for anyone else, LOL. As I've said I have never ascended without wanting to ascend. If that's not good enough then something is wrong somewhere