John I think you could add a bungee before the cleat. Fasten the bungee to the line by lashing it on both ends with a strong thread (I glue the thread on the line also) make the bungee shorter than the line so the line has an extra loop which allows the line to lengthen as the bungee is pulled (when it hits kelp adding extra pull force). You would need to experiment with the bungee size I think the stuff I use is about 1/8 inch midway between tent pole bungee and deck bungee. I do this on bow tie off lines that I put on most of my boats. I hope my description made sense.