A sandal system for athletic activities. The sandal system may include a sandal with a midsole having a cavity contoured to receive an activity-specific insole and a plurality of interchangeable insoles. Each insole of the plurality of interchangeable insoles may be configured for a specific activity, such as running, hiking, walking, water activities, etc. A sandal upper coupled to the insole has one or more straps configured for securing the foot of the wearer in the sandal during athletic activities. The sandal may also include an outsole for providing traction and wearability and a support component for providing support and stability. The outsole, the midsole, and the support component may be configured to include a fluid drainage system including at least one drainage channel and at least one outlet aperture. It is emphasized that this abstract is provided to comply with the rules requiring an abstract. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims (37 C.F.R. 1.72(b)).