A submergible activity platform for attachment to an associated structure on a body of water is disclosed. The activity platform for supporting persons engaged in water activities includes a platform area extending outwardly from and alongside the associated structure. A support structure is carried by the activity platform for mounting the activity platform to the associated structure so that the activity platform is located at a desired depth in the water when mounted to the associated structure. A walkway is included in for providing access between the associated structure and the activity platform when submerged. The activity platform includes a water activity section free of the walkway where water activities may take place. The activity platform also includes a plurality of water flow passages for allowing water to flow through the activity platform when submerged to reduce the force of water currents against the activity platform.