Next time you are on a dive boat or with a group of divers take a close look at what they are Next time you are on a dive boat or with a group of divers take a close look at what they are wearing, especially if you are in the tropics. Are they all dressed the same? Do they all look the same? From my experience, the range runs from just a bathing suit to a full 1/4-inch farmer John, with bodies that are thin, heavy or all muscle.
Why do divers wear weights in the same place?
If divers all have different equipment, dive suits and body builds, how can they all wear weights in the same place? Think about this for one minute. One diver is wearing a dive skin, another has a short-sleeved shorty with high cut legs. Another diver is wearing just the farmer john part of their suit and not a jacket. Another diver has on a long sleeve 1/4-inch jacket only. Some BCD’s are negative while others have a tendency to float. No two divers are alike, yet all wear their weights pretty much in the same place.
Look at a fish. How does it swim? Horizontal in the water. Yes, trumpet fish stand on their heads, but they are not swimming! Fish are balanced, divers are not. The heavier part of a diver’s body is usually the legs. The lighter part is the chest area where the lungs are. So where do we put weight? At the heavier part. Where do we put air? At the lighter part. None of that makes sense. Basically, all of the dive equipment is saying “Stand up in the water.” Not only that but the tank located on the back tends to make a diver roll over on their back. There is no balance here at all.
Some divers are foot light, but a vast majority of divers are foot heavy to varying degrees. This means that when a diver stops kicking the feet tend to drop. In some cases, a diver’s normal swimming angle can be up to and in extreme cases more than a 45-degree angle to horizontal. This is not only uncomfortable but very inefficient. Inefficiency means more work. More work means breathing more and more breathing means more work to stay down. This turns into a loop which most people solve by adding weight. This increases the foot heavy problem, and the cycle continues.
Divers who are foot light have a solution, ankle weights. But what do foot heavy divers do? No one has really marketed anything to solve this problem. There is a buoyancy video that very clearly shows that swimming horizontally is correct and foot heavy or foot light is bad. If you are foot light it says use ankle weights and stops there. It says absolutely nothing about foot heavy. What do foot heavy divers do?
The solution is to add weights towards the top of the diver. I wear 12 pounds of lead with a 1/4 jumpsuit, and I am very foot heavy. Or as some would like to say, an air head. Regardless, my weight configuration is 6 pounds at my waist and 6 pounds toward the top of my tank. With this set up, I am horizontal in the water. To go down I simply swim down and to go up, swim up. Almost all the kicking power is used efficiently. Foot heavy divers tend to kick themselves toward the surface. Their answer? More lead?
Foot heavy divers also have great problems swimming in any kind of current, from mild to Foot heavy divers also have great problems swimming in any kind of current, from mild too strong. Think of an airplane which is flying along happily. Now bend that wing up and what happens? The plane goes up. The pilot can counter this with trim tabs, but the efficiency drops. Pilots also load planes for best balance. Divers just put weight around their waist with no thought to balance.
Balance is different from weight
A diver who is correctly weighted and balanced with 6 pounds on the waist and 6 pounds at the top would also be correctly balanced with 10 at the waist and 10 on top but not correctly weighted. Make sure you make a clear distinction between these two.
One can get into numerous formulas of weight distribution over the cross vector of air control flow factors divided by depths of compression volume with force equal to the division of the equation of nonsense, but fish don’t do that so why should we? Next time you are in the water try a simple experiment. Go down to about 20 feet and simply try to lie horizontally in the water. Absolutely no air can be in your BCD. Absolutely none, zero, zilch, zip. Why? Because how much is in it? The same as yesterday? The same as tomorrow? This experiment must have a constant and that can only be with an empty BCD. Don’t kick or try to do anything. Just see what your body does. This may take a few seconds, so wait. If you are foot light, then ankle weights might help. If you are foot heavy, then weights must be added somewhere else.
A short weight belt with one lead weight on each side placed between the tank and backpack, above the tank band, works very well (and it is cheap!). Some packs with twin bands have problems as do soft packs. Some ingenuity is required to see what your particular BCD will allow to work. Ideally it would be great to have either a BCD or a wetsuit top with many small pockets all over the top (front and back) where weights could be placed to accommodate each individual’s equipment and body build. As this isn’t the case a short weight belt is a start. One diver, as an experiment wore a weight belt up under the armpits. Just an experiment, but it helped! Weights in the top back of the BCD do not help the roll over problem but for whatever reason this has not affected my diving. Others have said they can feel this weight trying to roll them over. Again, this is a start. Until someone makes extra weight pockets all over the place there aren’t too many options.
Dropping weights in an emergency
Now the big argument. How does one drop the weights in an emergency? First, and most important, weights have only one function for most recreational diving. That is to make a diver as close to neutral as possible. Weight should not plunk you to the bottom and then put air in the BCD to lift you up. It’s right back to the first problem of weight on the bottom and air on the top.
There are counterarguments. It is unusual for someone to have all their lead on the top. If weights have to be dropped then those around the waist can be dropped. No, you don’t go head heavy. There are divers who wear no lead at all. How does someone who wears no lead drop a weight belt? If two divers are very well weighted and balanced, one with lead and one without, both can swim to the surface with virtually the same effort or lack of effort. Divers who are overweighted have to work to get up or drop belts.
Other complaints are about wetsuit compression. Wetsuits do compress but not to such a tremendous degree that 30 pounds are needed at the surface and half a BCD full of air is required at 60 feet. That is a bit of an exaggeration, but the point is there. Obviously full 1/4 farmer John will be quite different from a 1/8th inch shorty. Still compression is not so severe. I find with a 1/4-inch jumpsuit that through kicking a bit differently, breathing a bit differently, I can control this to most acceptable depths. Some have argued than changing your breathing is bad. Don’t we change our breathing all day long? Walk up the stairs and see what happens. Have someone scare you. I’m not talking about hyperventilating underwater or holding breath, just relaxing more.
Most divers complain about an area from the surface to about 15 feet of water. This “problem zone”, as I call it, is where divers have trouble getting down at the beginning of a dive and staying there at the end. For most divers’ extra lead is the answer. Unfortunately, this creates balance problems for the vast majority of the dive. Why be correctly weighted for a few minutes and out of balance for an hour or so? To get through the problem zone at the beginning of a dive it is critical that no air is in the BCD. A good strong surface dive can put divers deep enough underwater that a few kicks will propel them past the problem zone.
Old versus new BCD’s
Something else should be looked at now. Many older BCD’s have hollow hard packs. These packs hold air. Most have two tiny holes in the bottom to drain water. Heaven forbid anyone would want to get a dive boat wet. The only way to get air out is to stand on your head. The holes are too small so you may be standing there for quite some time. Drill these two bottom holes to at least a 1/2-inch diameter. Also drill two large holes at the top in the handle. Some packs have solid handles so look at yours. If so, find the highest point possible and drill one hole on each side. One manufacturer was clever enough to put a small hole almost at the top but on the inside, so it is restricted by the divers back. Many BCD backpacks are now made with holes top and bottom, but these should be much larger. The air should get out instantly. Many who have drilled out their packs have taken off two pounds of lead. Think about that. They were wearing two pounds of lead for the first few seconds of the dive. After the pack emptied, they carried two pounds of unnecessary lead. Many of the newer BCD’s now have a plate for a backpack and no air gets trapped at all.
Carrying unnecessary lead is like going shopping with $100 in pennies in your pocket. It makes you tired carrying it around. When you get tired you have to work harder to get things done. Work means breathing more which means floating more. The more you float the harder you have to work and once again a vicious cycle begins.
Are you floating upwards?
The next part of the problem occurs when divers get back near the problem zone at the end of the dive. Here the main complaint is tanks getting lighter. Tanks do get lighter but only one breath at a time lighter. It is always interesting to hear someone say, “When my tank hits 1000 psi I shoot to the surface.” Are they saying that at 1001 psi they can stay down? Something is wrong here. My suspicions are twofold. First anyone who is naturally foot heavy tends to kick to the surface as already discussed. Compound this with a slightly lighter tank and shallower water, many divers simply kick to the surface. Second, many still have air in the BCD adding to the problem.
Try another experiment. When in shallow water just stop. Do your feet sink? For many this sends a signal to their brain that they must be floating towards the surface. If their feet are sinking, then their head is shallower than their feet. They aren’t getting shallower, but they think they are. The immediate reaction is to try to kick back down. Try kicking to get down when your head is pointing up. Also not wanting to “float” to the surface can put a bit of adrenaline in the system which makes one breathe more and here we go again.
Relation between fins and buoyancy
Use of fins, as trivial as it may sound, is related to buoyancy more than one may think. The more efficient a kick the less work, the less work, the less breathing and so on. Watch other divers underwater. See how they kick. Is it efficient? Are they moving along effortlessly or kicking like crazy and hardly moving? Almost everything one does underwater is related to buoyancy. The less efficient a diver is the more they breathe. Here we go again. The more they breathe the more they float…!!!
This is just a small sampling of what can be done and a few options to try. Some things work great for some divers and other things for other divers. Without experimenting though, one would never progress.