Tag lines (single layer flat polypro webbing) hang of the tube tips and sides, providing something to grab and use for towing. I use 7' on the tips and 6' on the sides. When I grab a cat I usually grab the tag, wrap it around my footbar, step on it and then row it in. Much more control once you have the boat than pushing but it does mean off the oars for a spell. Conversely a swimmer can grab a tagline too, to help them get close to my boat. If someone is upside down on their boat they can grab a tag too and get towed.
I am a river, babe - I've got plenty of time, I don't know where I'm going, I'm just following the lines..... - "We are water" by Shaye