Subtitles section Play video Print subtitles water skis were in invented in 1922 by a man name Ralph Samuelson. With his brother pulling him by motor boat he tried first with skis made of barrel staves then with snow skis then with skis he made out of pine boards 2.4 meters long. This type of water skiing is called slalom skiing. Winding through a course on a single water ski. One foot behind the other in boots mounted to the ski. The core of this top of the line slalom skis is high density PVC foam. Exceptionally strong, yet light weight. A computer guided machine cuts the ski shape. Then pockets to receive various components. Workers flip the core upside down and the machine shapes the bottom. Workers then turn the core right side up again. And fill the pockets with glue. They insert an alignment tab in the tale pocket, to help correctly position the core in the mold. They install fiberglass neon blocks. These will anchor for mounting the skis boots and the fin. Now they begin building up the water ski with multiple layers of carbon fiber. An ultra strong fabric. They apply the first layer to the bottom. Wrapping it around to the top. This will prevent the ski from twisting. After stapling down the carbon fiber and trimming off the excess they saturate it with resin and apply carbon fiber to the top of the ski. Depending on the model and the performance specification they wrap the core in up to seven layers of carbon fiber controlling the flex and additional areas along the way with additional patches. Then they top the ski with woven synthetic fabric, to prime the surface for the decorative graphics. On the bottom of the ski they apply a sheet of super light weight polymer. It creates a white background to highlight the sheet of decorative graphics. They coat it with a special resign which cures into a hard hydro dynamic surface, that increases the skis speed. The graphic design that is on the top of the ski is printed on nylon. They mount it to the top part of the ski shape mold. Then lay the wrapped core into the bottom part. A heated press closes the mold. Compressing the contents under high pressure for nine minutes. This bonds the layers which forms contours in the ski and adheres the graphics. The pressure squeezes out excess resin along the perimeter. So once they remove the ski from the mold they cut of the excess with a band saw. Then with a custom made router bit they precision trim to exact specifications. Next, a three faze filling of the skis edge. First with a large file, then a small file, then a razor blade or medium grip sand paper. Then with the help of a template they drill 18 reinforced holes into the ski. They screw a threaded insert into the whole and it locks into the block. There are more inserts than required this gives the skier different positioning options. Now the last edge sanding with fine grit paper. After wiping the ski down with an alcohol cleaner they install the final but most important component, the fin. Its made of aluminum which is chemically treated to be ultra resistant and anti corrosion. The fins position critically effects the skis traction and stability so the use a micrometer to measure to the millimeter. Securing the fin in with in the design engineers specifications. Non the less competitive water skiers adjust the fin to their own preferences. In hopes of leaving competitors in their wake.