If you don't like clove hitches, how about some double-sided velcro? Buy it in 36" long strips in Home Depot, hang the fenders from it. Pull it up over the lifelines and one side sticks to the other, so you can just "stick it" instead of tying a knot at whatever point you want.
Or you could just do the proper seamanlike thing, replace those defective admirals. :-)