The expert riggers at APS make this double function Velcro keeper. It is great for securing your spinnaker halyard before and between hoists.
While going to weather, lock in the halyard in place by Velcroing the keeper around itself. Just prior to setting the kite, Velcro the keeper flat and the halyard will pull free during the hoist. Tie it to your life line, launching bag or companionway.