There are many options for whitewater rafting in Costa Rica.  These rafting trips are good for those living in Costa Rica as well as visitors.  It is possible to go rafting from just about everywhere you are in Costa Rica. Those who are flexible with the area to to go whitewater rafting from may choose from the different characteristics of the different rivers.  Most rivers in Costa Rica are generally between class 2 and 4.  But some of the rivers offer class 5 rapids for these rapids you should be a much more advanced rafter. Class 2 to 3 rapids are good for families with younger children.  River conditions can also change from the rainy season and dry season. When making reservations online the operator lists the minimum age and conditions for date selected.

You will be rafting through rain forests on most of the rivers. This  allows you to experience and see abundant wildlife and birds. In calm areas that you may be able to jump in the water and float with the raft

The most rivers for rafting are Sarapiquí, Reventazón, Pacuare, Savegre, Tenorio, and Balsa.  For those in San Jose probably you best options are Sarapiquí and Pacuare, I have rafted on both and enjoyed both.

Below are some of the rafting tours as an affiliate, I do receive compensation for reservations made and traveled on.

Rivers Grades of Rafting
Sarapiquí X X
Chirripó X X X
Reventazón X X X
Pacuare X X
Pejibaye X X
General X X
Savegre X X X
Naranjo X X X
Frío X X
Corobici X X
Tenorio X X X
Tempisque X
Balsa X X X