Abstract: A universal adjustable platform providing a horizontal surface for mounting equipment on the inside of a boat hull is disclosed. The platform has a back plate mountable to the boat hull preferably near the gunwale. A support plate is pivotally attached to the back plate by matched lugs on each plate rotatably joined by pivot pins. A support arm is connected between the back and support plates forming a diagonal brace. The support arm is pivotally connected at each end to a respective plate via a lug and clevis arrangement. The support arm is formed by two elongated shafts arranged in a parallel, spaced apart relationship interfitting within a clamping block. The elongated shafts can slide within the block allowing the length of the support arm to be adjusted in response to adjustment of the relative angle between the support plate and the back plate. The clamping block is formed from two oppositely arranged side portions which are bolted together.