I have since found this method documented but the first time I saw it Liz 'invented it' on the fly. This is a way to adjust the snugness of the bowline on you winch or for that matter whatever you have tied it to. Tie the bowline as ususal. pull the top of the eye and the bottom of the turn apart then pull on both of the strands exiting the loop to capsize the knot. Then snug it up and reset it.