What is the difference between Balsa and Sarapiqui River?

Both rivers have different sections we raft according to the chosen level of rapids, also both rivers are dam controlled to produce hydroelectric energy, it means the water level changes during the day according to energy production.  

The rapids on Balsa River are more predictable and easier to maneuver for the guide,  making this section an universal rafting section, it means we can take everybody, and the guide is more comfortable to adjust the level of action according to passenger’s skills, experience and paddle reactions. At this river we offer the next levels: rafting class III & IV, and rafting class II & III.  In the other hand at the Sarapiqui River we just run the section with rapids class IV, making this section more recommendable for adults, in good physical shape, because we must paddle harder compare to Balsa River, due to the gradient of the Sarapiqui River and the type of obstacles, this section is the most challenging. NOT recommended for seniors, kids or people with low mobility or overweight.