Swimming in Currents: Attempt to Explain

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As a disclaimer, I suck at math, I suck at swimming in currents, and I am not a math teacher. At the Patriots Half this weekend, we were challenged to come up with an easy way to explain swimming in currents. This is my attempt. Also, please note that some things are not drawn to scale/properly. I'm attempting to explain the idea of swimming in currents while avoiding math/numbers.

Below is an example of a swim route. The wiggly yellow man is the finish. The yellow triangles are turn buoys and the orange circles are sighting buoys. In aqua is the current. The dashed lines are the vertical and horizontal motions of the current, and the solid line is the resulting current. In this example, swimmers have to swim at about a 45 degree angle to the current on the trip out to the third buoy and back to the finish line. We will address the final leg back to the finish line.

In the dashed red line below, the swimmer is just thinking, "I have to swim straight to the wiggly man!" and is not thinking about aiming left or right. The dashed aqua line is the horizontal direction of the current from above (notice I'm not using numbers, just relative direction/effect, I'm also ignoring vertical motion because we're more concerned about the horizontal motion). The solid red line is the resulting direction of the swimmer. The swimmer will be pushed/pulled by the current to the right as he tries to swim forward.

In the dashed green lines below, the swimmer is thinking, "I have to swim toward the shore, but also toward the buoys. I have to overcome the strength of the current to arrive where I want to near the shore." The swimmer is swimming enough to the left to overcome the current push/pull to the right. There is a dark green dashed line that shows the net horizontal motion of the swimmer. The solid green line shows the estimated line the swimmer will swim if his velocity and the current's velocity is constant.

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