Am I overweighted

[Eric Sedletzky]

There is one very simple rule about proper weighting:
At the end of a full length dive you should be able to hold a stop at 15 feet with your BC and or any other air holding device completely empty and be able to control your buoyancy holding a perfect stop with your breathing alone.

Everything else means nothing as far as what suit, what tank, how much gas, what BC, whatever else. There are so many variables that there is no way to armchair advice over the internet about how much weight you need, blah blah blah.

Like I said, the one true way to know is to check your weight at the very end of a FULL LENGTH DIVE. Why a full length dive? Because wetsuits compress over a period of time and stay compressed longer than it takes you to come up. Also they cool off and that that takes time too, as in the length of a dive. When they cool they also loose buoyancy because the size of the gas bubbles inside the material gets smaller which means the material is not as buoyant. All these things need to be factored in, that's why I say weighting needs to be checked at the end of a full length dive at depth.

One more time: You should be able to control your buoyancy with your breathing alone at 15 feet at the end of a dive with your BC completely empty. This is perfect weighting and cannot be improved upon.

 

[MauiScubaSteve]

How often do you find just one "perfect" rule of thumb for anything?

One answer might be, only in that oh so elusive "one" perfect world, that actually does not exist.

 

[Antagonist]

There is one very simple rule about proper weighting:
At the end of a full length dive you should be able to hold a stop at 15 feet with your BC and or any other air holding device completely empty and be able to control your buoyancy holding a perfect stop with your breathing alone.

Everything else means nothing as far as what suit, what tank, how much gas, what BC, whatever else. There are so many variables that there is no way to armchair advice over the internet about how much weight you need, blah blah blah.

Like I said, the one true way to know is to check your weight at the very end of a FULL LENGTH DIVE. Why a full length dive? Because wetsuits compress over a period of time and stay compressed longer than it takes you to come up. Also they cool off and that that takes time too, as in the length of a dive. When they cool they also loose buoyancy because the size of the gas bubbles inside the material gets smaller which means the material is not as buoyant. All these things need to be factored in, that's why I say weighting needs to be checked at the end of a full length dive at depth.

One more time: You should be able to control your buoyancy with your breathing alone at 15 feet at the end of a dive with your BC completely empty. This is perfect weighting and cannot be improved upon.

Thanks a lot! I never learned that. I look forward to going diving as soon as i can to get my wife and I weight correct.

 

[DevonDiver]

For those that don't know, properly weighted = float eye level holding a normal breath, empty (50 bar, 750 PSI or less) tank, and empty BCD, no finning. Double check = slowly sink when you exhale at the end of the check.

lly
That is what is taught on PADI courses, but it is not the optimum method for precision tuning your weighting.

Check out my link in post #5, for a description/comparison of methods.

Ideal way is to maintain a stop at 5m, empty BCD and with your cylinder nearly empty. Gradually experiment by removing weights, until you can no longer hold the stop comfortably. When you reach a stage with minimum weight, but can still maintain a shallow stop with a nearly empty cylinder, you know you have enough weight, but no surplus. Easy as that

 

[TSandM]

What I thought was a really clever way of determining weighting was described here a while back: Thread a weight belt with your best guess of your weighting, plus a number of small additional weights. (So, for example, if you think you need 30 lbs of weight, you could put two ten pounders and a five, and then a bunch of twos on the belt.) With your gear as it would be at the end of a dive (500 psi in tank, no air in BC and minimum air in dry suit, if used) get in shallow water holding the end of the weight belt. Maintain a normal breathing pattern, and pull up on the weight belt until you are underwater. However much weight is off the bottom, that's what it takes to make you neutral in shallow water with an empty tank! This is really easy for someone with integrated weights or carrying a weight belt to do, because you can actually dive until your gear is well saturated, and at the end of the dive, have someone bring you such a weight-checking belt -- get neutral, hold end of belt, and ditch your own weights, and see what happens.

 

[kmurray719]

How often do you find just one "perfect" rule of thumb for anything?

One answer might be, only in that oh so elusive "one" perfect world, that actually does not exist.

Agreed. All of the "perfect weighting" methods and rules are useless for shore dives where we often spend the last 10-15 minutes of the dive at a depth of 10 feet or less. If I had the "perfect" weighting for those dives, I would have to do some really long surface swims! The "holding a safety stop at 15 feet with no air in your BCD" method may work perfectly well for boat dives, but not for most of my shore dives.

 

[boulderjohn]

Isn't proper weighting being taught in OW classes nowadays?
I would think that this should be one of the more important topics taught, since proper weighting impacts buoyancy control...and safety.
My OW instructor had us do at least one weight check at the beginning of a class dive and another one at the end of the dive. By the end of class, we all knew how to conduct a proper weight check.

A proper weight check is not only supposed to be a part of the class for all RSTC agencies (including PADI, DSI, SSI, IDEA, and PSAI), it is supposed to be emphasized. Students are supposed to do a weight check at the beginning of every OW dive in addition to the pool training.

I have seen too much evidence that this is not being done, though, and I think I can point my finger at a probably reason.

About a year ago I was asked to fill in for someone who was assisting another instructor in a large class. The instructor and I have a very different approach to instructing, but he was in charge and I followed his procedure. When it was time for the weight check, he commented to me that he "knew" this is "just a waste of time" but he knew it had to be done to meet standards. Alarmed, I told him I thought it as very important, and he let me lead the exercise. I got the students to shed quite a bit of the weight he had put on them in the beginning of the class.

He had to put the extra weight on them because, like most OW instructors, he taught students to do their skills while planted on their knees. It takes a lot more weight to do skills comfortably on the knees than it takes to dive. If instructors have students do all their skills on their knees (and many of them still do the skills on the knees in the OW dives), then they will probably have them intentionally overweighted throughout their instructional experience. It just makes it so much easier that way. I assisted in all his pool sessions, and I never saw the students do anything in the pool without being planted on the bottom other than a single swim around the perimeter of the pool, during which they exhibited absolutely nothing resembling buoyancy control.

Instructors who never teach skills on the knees or who transition quickly from instruction on the knees to a normal swimming position find that students perform skills much more easily while properly weighted. A good weight check is thus important to us, for we want our students to be at their best. It makes the transition to good buoyancy control and swimming position very much easier. Our students can swim with good trim and good buoyancy control long before the end of the confined water portion of the class.

 

[Bubbletrubble]

@boulderjohn: John, please continue to speak on this topic with instructors within your organization and outside of it. It's an important dive safety issue. Occasionally, I'll do a dive with a recently certified diver at a local dive site. I do this in an attempt to model good dive behavior outside of OW class. Newbies need to know that at least some experienced divers do the things that all OW instructors should be teaching: extensive pre-dive functional checks on their gear, pre-dive gas/profile planning, respect for deco limits, and comprehensive buddy checks. The first topic we discuss is proper weighting. I wish I had a nickel for every time I got a "blank stare" back when I asked them specifically how they conduct a weight check. More than once, I've been asked by a newbie with whom I have never dived before: "Do I have enough weight?"

I consider the weight check a fundamental dive skill. I make them promise me that they'll practice it for the next few dives. It's something that they should feel very comfortable doing.

 

[Eric Sedletzky]

Agreed. All of the "perfect weighting" methods and rules are useless for shore dives where we often spend the last 10-15 minutes of the dive at a depth of 10 feet or less. If I had the "perfect" weighting for those dives, I would have to do some really long surface swims! The "holding a safety stop at 15 feet with no air in your BCD" method may work perfectly well for boat dives, but not for most of my shore dives.

Actually, checking weighting for the 15 foot no air in BC method is not useless at all for shore dives where you may want to be neutral at 10 feet with no air in BC or even 5 foot with no air in BC.
At least you will have a starting point from which you can add a few pounds of weight to compensate for the 5 to 10 foot shallower dive, plus you will know what your weighting is supposed to be if you do get on a boat.

BTW, 99% of my dives are shore dives in very similar conditions to MA. 48 degree water wearing a two piece 7 mil.

 

[kmurray719]

Actually, checking weighting for the 15 foot no air in BC method is not useless at all for shore dives where you may want to be neutral at 10 feet with no air in BC or even 5 foot with no air in BC.
At least you will have a starting point from which you can add a few pounds of weight to compensate for the 5 to 10 foot shallower dive, plus you will know what your weighting is supposed to be if you do get on a boat.

BTW, 99% of my dives are shore dives in very similar conditions to MA. 48 degree water wearing a two piece 7 mil.

I guess I wasn't quite clear--I wasn't saying that a weight check at 15 feet was useless for shore diving, I was addressing this statement:

How often do you find just one "perfect" rule of thumb for anything?

I often see people using "neutral at 15 feet with an empty BCD" as the "right" amount of weight to use, and saying any more weight than that means you're overweighted. I was pointing out that that "test" will not always produce the "perfect" amount of weight for every dive situation. Having a starting point for weighting yourself is important, but the "right" amount of weight for each dive is not always the same.