Adventure travel is now becoming popular with many teenagers.Gone are the days when you could only go on vacation with adults. From heli-hiking (helicopter flights and long distance walks) and mountain climbing to white-water rafting or whale-watching,adventure vacations can now give you more variety and excitement thanvever. You don't have to a top athlete to go on a walking,sailing,or sports vacation,but you do need to be well prepared in lots of ways. If you and your friends are planning an exciting trip somewhere this year,there are a few things you ought to know before you set off.