Is surfing, sledding and skiing permitted on Shabbat?

Surfing on water is prohibited for several reasons, whereas sledding on snow, in general could be allowed if there's an eruv, especially for children where we don't want them to harbor negative feelings towards the Shabbat (especially in Israel where snow is a rare treat for children). Nevertheless, if going sledding involves a lot of preparations, and you "get into it", so that it preoccupies one so much so that you might even forget that it's Shabbat, it may fall under the category of "uvdin d'chol". Accordingly, it's clearly preferable not to, but a local rabbi, who can take all of the factors into account, has the "final call" on this decision.