Abstract: An apparatus for reeling and unreeling a flexible cover sheet for a swimming pool. The apparatus has two wheel supported carriage frames at opposite ends of an elongated drum and a stabilizer tube. The elongated drum is coaxial with a front pair of wheels and rotates independently of the wheels. A stabilizer tube is coaxial with a rear set of wheels in unison with them. A drive assembly on one of the carriage frames is operatively connected to the drum. It may be manually operated to reel an elongated flexible pool cover onto the drum. As this is done the cover will pull the carriages along a straight path to the point of connection of the cover end. The carriages are moved outwardly from the fixed cover end to play out the cover over the pool. Both the cover and the rear pair of wheels serve to maintain the drum in a perfect transverse orientation relative to the length of the pool cover sheet so the carriage will track straight and the cover will roll evenly onto the drum.