How it works is impressively simple. Using a spinnaker halyard as an example, first wind a bunch of turns on the drum. Attach the spinnaker halyard to a small loop on the drum, and you’re set to go. As you raise the spinnaker, the halyard tail is rolled onto the drum. A little experimenting will tell you how many pre-winds you need. The other loading option, especially if the drum is located in a place that is difficult to access, is to sky the halyard, attach the tail to the drum and then, as you pull the halyard down, the drum will automatically wind. Caution: there will always be a little upward pull on the halyard, so be careful not to let it hang free or you’ll be climbing the mast to retrieve it.