Nordic skiing is a type of skiing where the heel of the boot is not attached to the ski. Nordic skiing is still considered to be a winter sport or activity.
wake boarding and water skiing
No jet skiing is not a sport.
Water Skiing briefly made an appearance in the Olympics in 1972 but only as a demonstration sport. It is not a sport in 2012 as well ;_; In order for a sport to be recognized it not only has to be popular but meet IOC Standards.
Depends on length of exercise.
swimming water polo surfing water skiing
Biathlon can be both a summer (running/shooting) and winter sport (skiing/shooting). In the olympics however Biathlon is considered a winter sport because they only do cross country skiing and shooting.
Skiing originated in Norway, and it was used by the people there to get along quicker while hunting. It is also considered the worlds oldest sport.