This sort of "leash" is very popular with instructors and whitewater kayakers who use a short tow or "cow tail" for towing others short distances.

One end has a SS D- or O-ring, the other has a large 'biner (usually big enough to clip onto a paddle shaft).

I first used one as a sled dog leash!

: If you don't mind doing a little sewing, you could try tubular webbing with
: bungee cord fed through the inside of the webbing. The bungee is cut
: shorter than the webbing, then sewn in at the ends of the webbing. The
: tubular webbing "accordians" around the bungee cord when
: relaxed. The short bungee pulls the toggle tight against the boat. When
: lifted, the bungee stretches and the weight is on the tubular webbing.
: Any one with a large rowdy dog might consider trying this method to create a
: "shock absorber" leash using several bungees for resistance. It
: worked great with our sled dog that thought resistance from behind meant
: "full steam ahead".