A lot of watersports involve the wind, like kite surfing and windsurfing. All of that wind pummeling your hands and face can be pretty brutal and lead to some red marks. There are some things that can be worn like goggles and gloves to protect yourself, but in hot destinations, this can be less than ideal. Vaseline can help with this by providing a protective barrier that wind cannot get through.
Simply dab some on the top of your hands and your face to help protect it. Be careful to wipe it off of your palms; otherwise, holding on to anything will be impossible!