You probably have heard about tow-in surfing. With muscle power alone the surfer can’t make enough speed to get picked up by the wave. The solution is easy, the surfer is towed in onto the wave by a wave runner. The surfer is now able to get bigger waves.
I didn’t know that this was possible with windsurfing equipment. Kauli Seadi did a tow in session at big wave spot Jaws. On 1:03 you can see how he is towed in.