Ironic, but I found towing my kayak is easier than one of those common yellow dive flag/floats. I'd hate to have it stolen though! Some friends use an inner tube with a milk crate lashed in the middle and a retractable clothes line reel mounted in the crate. It keeps a reasonable amount of tension on the line and retracts as you surface. I don't think there is enough tension to "pull" you up, but mostly they are shore diving and just swim in shallow. Moight not work for all locations.