Swimming is a pervasive American pastime. Many know how to swim, or at least the basics of staying afloat. However, what many are unable to do is execute a dive into a body of water. This skill is useful for any avid swimmer: from the recreational pool dweller to the elite racer. A proper dive requires adherence to proper body mechanics and setup. At the end of these instructions, you should have all the knowledge needed to execute a technically correct dive. However, simply reading is not enough: practice will be required!
Step 1: The Approach
Observe your takeoff area. Ensure that the depth of the water you are about to enter is at least five feet deep. If not, avoid diving in: dives executed in depths shallower than five feet carry an increased risk for head and neck injuries, especially in novice divers.
Analyze your starting area. Competitive pools will have raised 'takeoff blocks': these are large plastic and aluminum stands off which competitive swimmers start their races. Other pools will simply have either a concrete or aluminum lip at the edge of the pool. These two varieties of starting areas require very different schools of thought. Given the propensity for pools to have takeoff blocks, this Instructable will strictly cover the steps to diving off of a block. Not only are takeoff blocks more widespread, they are also more nuanced and their use requires more advice.
Takeoff blocks will often have one or two ladder steps to assist the swimmer in reaching the platform. Be advised: these steps, though frequently covered in tractive rubber, are extremely slippery. Be sure to grasp onto the sides of the platform so as to avoid slipping and falling. Once you are securely on top of the platform, the real nuances of the dive begin.
Step 2: Taking Your Mark
In competitive swimming, the starting judge will instruct the swimmers to "take your mark" after they have stepped onto the starting block. This refers to a kind of bracing in which the swimmer coils up like a spring, building up potential energy and preparing to convert that to kinetic energy.
To take your mark, first locate your dominant foot. Your dominant foot will be on the side of your dominant hand (e.g. the hand you write with). Place your dominant foot at the front edge of the block, just enough so that your big toe hangs over the edge. Curl your big toe over the front edge of the block: this will allow for better traction and bracing for takeoff.
Place your second foot about 18 inches back. The role of your second foot is to find the median of balance and power. If your second foot is too far forward, it provides a great deal of power but almost no stability. If it is too far back, it helps stabilize your body but provides no power upon takeoff.
Now, you must place your arms. Your arms should be spaced shoulder width apart as you bend over to grasp the edge of the block. Your dominant big toe should nearly bisect the space between your arm, though it may be a little closer to your dominant hand. As your hands grasp the front edge of the block, ensure that your elbows are bent slightly. The degree of bending is a personal choice, but ensure that your elbows are not rigid nor locked.
Step 3: Launching
With your eyes staring directly down at the water, launch off of the block. This launch should be initiated by your dominant foot. If your dominant big toe was gripping the front edge of the block properly, this initiation should provide most of the power needed to propel yourself into the air.
Your hands are your secondary power sources: they can be used to aid in pushing off of the block, but take care not to overexert. Your hands will help guide you when airborne, so use them wisely during the takeoff.
Your secondary leg can provide a touch more power, but its main service is still in stability and preventing lateral motion. Be sure not to overexert this leg so as to avoid skewing your dive left or right of your intended path.
It will be natural to want to jerk your head up upon the launch, but refrain from doing so. Lifting your head up not only introduces new aerodynamic forces that slow your dive, it also throws you off your trajectory. Keep your head parallel to the surface of the water at launch to preserve your line.
Step 4: Airborne
Now that you are in midair, a great deal of things can go wrong. As mentioned in the last step, maintain a head angle parallel to the water at all times. This will ensure a true line of trajectory, and it will ensure that you do not enter the water at too sharp an angle and go too deep too fast.
Engage your abdominal muscles. These are your stabilizers in the air just as your secondary foot was your stabilizer on the takeoff block. Though your abs are engaged in the air, don't engage or tense up any other muscles. In order for your body to follow a line of trajectory conducive to a clean entry, your muscles need to be relaxed enough to move with gravity.
Keep your arms beneath your torso and avoid flailing.
As you near the surface of the water, arch your back slightly. This allows your body to avoid diving straight to the bottom by slowly leveling out upon entry. Shift your arms upwards into a streamline. This entails clamping one hand over the other above your head and squeezing your ears with your biceps. This will facilitate your clean entry into the water.
Step 5: Entry
With your hands in a taut streamline, your abs engaged, and your back slightly arched, you will enter the water cleanly. It may be tempting to pull your head out of the streamline, but such a move would throw your body's entire alignment off. As your head enters the water, continue to directly face the bottom of the pool. Your arched back should make it so that you are submerged no more than three or four feet from the surface. As soon as your legs enter the water, begin to lightly kick and soon you will be at the surface.