Abstract: The boat trailer includes a housing, for receiving a boat therein. The housing covers and supports the boat for storage or transport thereof. The housing includes an antechamber, an upper wall, a pair of sidewalls and at least one rear door. The trailer includes a front chassis and a rear chassis slidably engaging the front chassis, the housing being mounted on the front chassis. The rear chassis may be secured to the front chassis when drawn fully forward into the housing. The rear chassis supports a boat cradle or the like. A motor is housed in the antechamber and drives a linear translation system to extend the rear chassis from the trailer and draw the rear chassis back within the trailer. The linear translation system may be a chain and sprocket system driving rack and pinion gearing.