no, i wouldnt ski at all. your spleen is enlarged when you have mono. Your spleen filters toxins out of your blood. You can live without a spleen, but your body wont recycle the iron in your body nor filter your blood. I went to high school, with a two girls who lost their sister when she went waterskiing with mono. Is your life really worth not missing a couple of months of skiing? Take it from a guy who has had mono 3 times. I got a pretty good understanding on this topic.