Wakeboarding, wiffleball white water rafting, water skiing
There are lots for example: fishing, canoeing, speedboating, water skiing, wakeboarding and much more. Well depending on the size of the river.
Skiing is def. easier than snowboarding!
wakeboarding
Surfing, Wakeboarding, Swimming and Jetskiing.
I believe it's illegal to surf behing a boat. unless you mean wake-surfing or wake-skating or wakeboarding. I can't help you with that. But if you browse YouTube or get the O'Brien Skiing DVD I bet you'll find something. The O'Brien DVD covers everything from Water Skiing through Wake-Skating.
skiing, easier to pick up on
look at how to wake board on this site
Malibu Boats is a USA based manufacturer of recreational boats. Their head office is located in Loudon, Tennessee. Besides recreational boats, they also manufacture sports boats like for water skiing and wakeboarding.
The importance of strength in skiing is that strength can make skiing easier while navigating slopes and is somewhat similar to endurance in skiing.
Snowboarding can be done on snow. Waterskiing can be done on water.
Wakeboarding HD happened in 2010.