From Tom Bamonte:
Over the past few weeks I've needed to employ a contact tow on a few occasions. I've been using something called the Mini-Shockle and it worked very well. You can find it here:
The Mini-Shockle is a dressed up firm bungee cord with carabiners on each end. It is easy to deploy and
seems strong enough for contact tow purposes. The Mini-Shockle is handy to have around. When I had to drag my kayak through some shallow water I just clipped it to my bow toggle and I was set to go.
Thanks to Jim Tibensky for the tip.