Abstract: A stair assembly to enable easy boarding and deboarding of a watercraft includes one or more step members hingedly fixed within a cavity formed with the bow, side walls or transom of the watercraft to permit the step members to swing, in a rolling movement, from a compact stowed position to an extended, deployed position wherein the stair assembly extends outboard of the watercraft. The step members are specifically shaped and configured to conform with the bow, side walls and/or transom when in the stowed position to thereby fill the cavity and provide an integral, seaworthy structure.