Seafarer 24 Halyards
The new high-tech no-stretch lines (starting with Sta-setX and then on up the super-fiber scale) should be more than strong enough starting at
3/8" dia. (Some of them could lift your boat !) You may want something thicker than that to make it easier on your hands, but make sure the thicker line will fit through your halyard sheaves and onto your halyard cleats! The simplest thing to do would be to buy a hundred feet or so of line and cut off the amount you need. You can use the leftover for rigging a sun awning. Halyards should have an extra few feet at the ends so you can shorten them and/or reverse them a few years from now and not have to buy new ones when these start to wear. We''ve used all fiber (Spectra with a poly cover) halyards for our spinnakers for the past four years and haven''t had to shorten or switch them yet.