When it comes to outdoor thrills it’s tough to beat whitewater rafting, especially in the height of spring.

As the snow melts and the spring showers bring rain, rivers run powerful and quick with tons of water. The increasingly popular activity of whitewater rafting is considered by many to be dangerous—and it can be—but there are many options ranging from slight currents to all out, life-threatening rapids.

Each area is ranked based on degree of difficulty and danger. The scale begins with class I Rapids, which usually have small waves, few obstacles and a very low risk of injury. At the extreme end of the scale, you’ll find class VI Rapids, which are considered extreme and exploratory. Even the most skilled paddlers are encouraged not to enter VI rapids, as the risk of major injury or death is high and the chance of rescue is very low. Most experts stick to class V rapids.

Whatever your skill level, if you’re interested in whitewater rafting, there’s a river just right for you. We’ve highlighted some of the best whitewater rafting rivers in the world to get you started on your planning.