Even though the term may not be common up here in the land of the America’s Cup, I’ve heard headsails called “headies” by those sailors from down under who seem to keep winning everything. There sure are a lot of names that these sails are known by, compared to that workhorse piece of canvas aboard, the mainsail. A small change in a headsail can make a tremendous difference in a boat’s performance, especially upwind, so it’s not surprising that sailors are a bit obsessed with them. Here are a few names you may have heard: Yankee, drifter, windseeker, #4, genoa, ghoster, blade, 135%, storm jib, working jib, reacher, screecher, blooper, big boy, gennaker, jib top, staysail, gollywhomper, code zero, spinnaker, asymmetric spinnaker, cruising ‘chute.
The term “headsail” refers to any sail set foreward of the forewardmost mast. The next most general term is “jib.” According to the PHRF rules, a jib is “any sail, other than a spinnaker, that is to be set in the fore triangle.” (“Other than a spinnaker” would seem to be an unnecessary refinement, since the spinnaker is flown outside of the fore triangle.) So a spinnaker is a headsail but not a jib.
All genoas are jibs, but not all jibs are genoas. A genoa is an overlapping headsail, where the jib may or may not be. The overlap referred to is that of the clew of the genoa, which overlaps the luff of the mainsail. A more specific way to describe the size of any jib is by a percentage, e.g., 135%. This number is the ratio between the LP of the headsail and “J.” The LP, or longest perpendicular, is the length of a line through the clew, perpendicular to the luff. “J” is the distance between the pin of the forestay and the mast.
Another common way of referring to headsail size is by numbers: #1 would be the largest jib on the boat, #2 a little smaller, etc. For spinnakers, the numbering may be S1, S2, or for asymmetrical spinnakers, A1 and A2. This system is relative to the sail inventory on a particular boat, so your #1 could be another boat’s #2.
The speed of the America’s Cup catamarans have made traditional spinnakers irrelevant and all headsails have lost their former pre-eminence to the wing. Us commoners can still have our blades and Yankees, however, until we go that fast.