When waterskiing you are being tugged behind a boat at high speeds on deep water. The forces involved then are very high and the water bellow quite traitorous. As such it’s important to try not to fall over and to make sure you’re in the right position when you do. At the same time the correct stance when waterskiing will help you to go faster, becoming more aerodynamic and reducing drag coefficient while allowing you to pull the handle taught and control your movement better.
The first thing to ensure is that you have a firm and tight grip on the handle and the rope. This can tug suddenly and forcefully as you go over waves etc and so it’s important to ensure that this doesn’t cause you to fall or to hurt your arms by yanking at the joints forcefully. The strongest position for holding the handle then is to keep your arms bent at 90 degrees at all times. This is an important tip that’s taught among beginner wakeboarding tips as well as waterskiing tips. In martial arts this is considered the strongest position for your arm.