They have a big drum-spool and a very long rope, run by an electric motor up at the club end. You need one person at each end, one to turn on the motor, one to lead the boat.

They just drag the rope down to the boat on the beach, the drum on freewheel, and tie it to the cat track ropes, or main beam, whatever, then turn on the winch and up she comes, at about a walking pace. The only drawback being they can only drag up one boat at a time and then take the rope back for the next boat.

It is not a closed loop system (like a ski rope tow) with another wheel on the beach, because of the huge tidal range, but that would be nice to install at a lake location where the tide won't cover it up.