Rafting is an adventure sport gaining a lot of momentum and popularity, especially in northern part of Nepal and India due to the immense heights from which the rivers flow through the Himalayas. An amazing activity of teamwork and swifting through the high and quick movements of water, rapids as they are called, with all the jerks, jumps and falls in the river, rafting is a very enjoyable and fun adventure activity to do.
I have done it several times in North of India and Nepal too. The most popular river in Nepal for rafting is river Trishuli, as it has many rapids, twists and turns and at the same time is not very dangerous. There are many resorts around truly which are on the way to Kathmandu from Pokhara or another way around. Depending on the length of time you want to raft you can choose the hours and the rapids. Generally, it is for 2 or 4 hours wherein you have a master who makes you learn the basics and commands throughout the raft whether to paddle, stop, go up or down etc.
The best is when 3 or 4 boats are rafting at the same time, they have competitions, games and many other things that make the ride more worthy. I did it with my other friends and also made some good friends there, this is what it generates be it teamwork, fun, enjoyment etc. As they say, just go into the waters and let it flow, but beware as the water would be cold :).