A harness system for supporting a person off of a ground surface. The harness system may include a seat supported by a strap attached to the seat. The strap may form one or more leg containing loops for keeping a person securely positioned in the harness. The harness may also include a climbing strap for securing the harness loosely to a support device, such as a tree, while a person climbs a support device. The harness may be secured to a person by tightening a waist strap around the person's waist. The harness system may include one or more modular pouches releasably coupled to the harness enabling the harness to be customized for a particular use. A shoulder strap may be used to prevent a user from falling out of the harness and to support the harness.