Adventure travel is now becoming poplar with many teenagers. Gone are the days when you could only go no 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 than ever.You don't have to be a top athlete to go on a walking,sailing,or sports vacation,but you do need to be well prepared in lost of ways. If you and your friends are planning an exciting trip somewhere this year,there are a few thing you ought to know before you set off.