Basic Principles

The basic aerodynamic principle behind these stroke mechanics instructions is aerodynamic lift. Most surfers probably think of their hands when paddling as dragging through the water or "holding onto" the water, propelling them forward with their "grip."

In fact the more efficient strokes use a combination of lift-based and drag-based forces to generate propulsion. The hand during the stroke is more like an airplane propeller than a big paddle wheel. It twists and turns and accelerates continuously from start to finish.

The basic continuous stroke cycle can be broken down into four parts: catch and down, in, up, and recovery. The first three are done in the water, the last over the water as the hand is brought forward again to start the next stroke. The first three strokes ascribe an 'S'-like curve in the water.

The Catch and Downsweep

Your hand enters the water and immediately begins to pull down and out. As this happens, your elbow begins to bend and your palm is pitched downward, outward, and backward. This continues until the hand reaches its deepest extent with the elbow slightly bent.

The downsweep comprises the first part of the 'S' curve of the hand, which has moved down and out and now is going to move up and in.

The Insweep

As your hand reaches the bottom of its downsweep it turns upward, inward, and backward, and accelerates towards the midline of your body until it comes even with your chest. The degree to which your hand approaches the midline of your board will depend on how wide and thick your board is -- longboards and paddleboards are difficult to paddle in this fashion while shortboarders and boogieboarders can develop a nearly normal swimming stroke.

The Upsweep / Power Stroke

When the hand has come in and up to even with the chest, it turns perpendicular to the bodyline and accelerates strongly and powerfully through the and towards the thigh.

This is the most powerful portion of the stroke. However, a poorly-executed catch or insweep can have a big effect on how powerful the upsweep is. The first two portions of the stroke 'set up' the last.

A good catch, downsweep and insweep will bring the hand into the most propulsive part of the stroke earlier and faster. More forward motion will be generated from the same effort as doing a drag-based pull where the hand pulls straight back to the legs immediately upon entering the water.

Keep the elbow bent through the upsweep until it passes your waist, then extend the arm and push the water back until releasing water and recovering at full extension.

The Recovery

The hand should release water as it reaches the bottom of the stroke, exiting cleanly and returning to the catch smoothly. Bend the elbow as the hand goes along the water surface, and keep the elbow high. Do not swing the arms wide but rather rotate the body over.

As you execute the recovery of one hand, your other hand should be performing its downsweep, so the rotation of your body will get your downsweeping hand deeper into the water as your other hand recovers.

Summary

Get your elbows bent and underneath your board. Strike a balance between keeping your stroke with a natural feel and changing your stroke to be more efficient. A better stroke will initially feel strange. On the other hand, forcing a stroke or thinking too hard about mechanics while paddling can make you rigid and inefficient. It's best to be efficient and smooth at the same time.