Harness
I would attach a harness with a roller fastener to the two stern cleats. That way the skiier would turn with the boat relatively level. These are available. Otherwise, you could just hank it onto one of the stern cleats. On skiing, use wide skiis and small people and you will be OK. A heavy skiier will drag down the boat. The Mac 26's are not ideal ski boats. It is possible. A float would be better to drag.