Have you ever watched a shark as it moves along the reef? You see its smooth almost majestic movements, the streamlined body, and the relaxed manner it moves into a school of fish. You know that it has power and great speed, however, the shark only calls on it when needed. The shark has evolved to be efficient under the water, scuba divers have not. We have to work at it to be able to conserve air and scuba dive longer.
The way we move through the water greatly impacts the energy we spend and the air we consume. It is a skill that takes time and conscious effort to learn and sadly many divers do not even try. Often, it is a case that we do not know how bad we really are, it takes someone to tell us or show us.
What is a proper form?
The proper form will keep you moving in a streamlined manner, much like your favorite shark. Your body from the head to your knees should form a straight line. Your head should be forward-facing and your knee bent to a 90° angle. This may sound easy but it does take a little work. When you first start working on your form, do not concern yourself too much that you are not horizontal. The position of your weights will affect the horizontal position. Once you have the form properly or at least close, you can adjust the weight trim.
Most people have poor posture, no matter how many times our mother told us to stand up straight. We will find that our muscles have remembered those positions we normally use. When we float, the body will relax but may not necessarily form the position we need. Many will find their natural position is with the rump up higher than the spine. This forces the legs down, now when we kick we are forcing ourselves up as well as forward. The best way to correct this is to arch your back slightly, square your shoulders and stretch your chest. This is the form you will see parachutists take in free fall.
Your knees should be bent so that your calves are slightly above your back and the ankle relaxed allowing the blade of the fins to be parallel with your body. Your hands are not a part of your propulsion underwater. They should be held in a streamlined position if they are not in use such as holding a gauge or a light. Many divers will hold the arms in front of them, one hand lightly grasping the other wrist. Arms at your side or folded across your chest are also popular means to stay streamlined.
I became certified at a local dive center near where I was living for a year. After becoming certified, many of my dives were with my instructor as the divemaster. We would spend our 5-meter safety stop working on my and my dive buddies’ form. The instructor gently controlled our body positions to help create muscle memory. That is something you and your buddy can do.
Using weights to adjust your trim and scuba dive longer
The article on buoyancy control briefly mentioned trim. Your body has a center of gravity (COG), a pivot point if you will. Like a seesaw, you want to keep the weight on either side in balance. The further away from the center of gravity the greater the impact weight will have. While the location of your dive weights is important, it has to be used in conjunction with other items. The cylinder is often overlooked as an element of trim. Its position can matter a great deal as it is on both sides of your COG.
If you find your trim changes between your first and second dive, the location of your tank may be the cause. Most BCDs have an adjustable loop that fits over the neck of a dive cylinder. You can use that strap as a guide to position your tank each time. When you find the proper position for your tank, tighten the loop. Each time you place your BCD on a cylinder slide the BCD down until the loop is tight before securing the dive band. Many times divers will let the boat crew change over the equipment and they may not be as detail-orientated as you should be.
The balance of the cylinder impacts your trim, however, as you start working on your trim its balance is less important than it is consistent. Some BCD’s have shoulder pockets for trim weights, weights added here will reduce a positive trim, one where your chest is higher than the COG. If your BCD does not have a shoulder pocket, you can purchase weights that will clip to your d-rings. Divers can place some weight on the tank or tank band. Weight added near the neck of a tank will bring the chest down and legs up. Weights near the tank boot will have the opposite effect.
As you move weights to different locations, remember that you must maintain enough weight on your weight belt or other quick releases to gain positive buoyancy in an emergency. You should also account for heavy gear. If you have a large dive light clipped to your BCD, not bringing it on a dive might affect your trim.
Streamlining your equipment is an important point. Like the streamlining you do with your hands, anything outside your body profile will cause drag, that will affect your profile. Keep hoses and gauges close to the body.
Do a five-meter equipment check
As a part of each of my dive plans, I add a stop at five meters both on descent and ascent. Before you start your descent, you should make a check on your equipment. During the descent, pause at five meters, become horizontal, check your trim and adjust your equipment if needed. On boat dives, the entry may have slightly moved your weights, and you might not notice it on the surface. After some practice, this stop will likely only take a few seconds. Check with your dive buddy and continue your descent.
Thanks to the widespread use of sports cameras, underwater video is not as expensive as it once was. The quality will not be the best, still, it is good enough to share your passion. Instead of taking selfies underwater, occasionally ask your dive buddy to take some video including you when you are not aware they are recording you. Examine the video and evaluate your form. Visualize doing it better next time.
My most memorable dive was my 30th dive, about 18 years ago. It was my first dive in the Bahamas, and the first dive where we were told to expect a number of sharks. It was also the first time where there was someone recording the dive. Back then video cameras were very large and very expensive. I spent a good portion of the dive watching the sharks, watching how smooth they were. After the dive, the divemaster complimented me on my form. When I watched the video that was taken, I was pleasantly surprised, even proud, of how good I looked underwater. It also showed me how most of the divers, even the experienced ones, took no care of their form.
Bad habits are hard to break
It is best to start applying these skills when you are first learning to dive. This gets you on the right path to having great form before bad habits create muscle memory. When that happens, it becomes more difficult to get the proper form. When you were in school, your gym coach was always preaching about form and basic skills. The same principles apply in this sport as well. A bit of a conscious effort as a new diver and periodically checking yourself as your diving continues will keep you in good form. A good form means less work, which results in longer dive times and less fatigue after a dive. The knowledge you gain controlling your buoyancy also reduces your risk of an uncontrolled ascent.
A little early work for a long time benefit.
Learning what it takes for you to have a proper trim, excellent buoyancy and a good form will take a little effort at first. A few minutes of a dive working on it will go a long way to mastering it. Once it is mastered, everyone watching the underwater videos will see you as the role model. The diver to follow.