Racers know that moving the genoa fairlead outboard on a reach improves boatspeed, but many cruisers overlook this and wind up sailing longer passages as a result. Whenever the wind is abeam or farther aft, it is best to open up the slot between the genoa and mainsail.
When a boat bears away from a close-hauled course and its mainsail is eased, the mainsail boom moves away from the centerline. If the genoa fairlead stays inboard, the slot between the main and the jib will become restricted, disrupting the airflow over the two sails and diminishing the sails lift and drive. Boatspeed will drop.
Ironically, when the genoa fairlead is moved forward as the wind moves aftwhich helps keep the top of the sail pulling correctlyslot constriction is made worse, because most genoa tracks curve inboard to match the deck configuration. The solution is to use a barber hauler. Usually this involves placing a snatch block on the toerail outboard of the genoa fairleads position on the track. To set up the barber hauler, first trim the genoa sheet properly, then run a second sheet from the genoa clew outside the lifelines, if possible, and back through the snatch block to a winch. Trim this line until it takes a load, then ease the genoa sheet. When the barber hauler takes the load of the sail, the clew will move outboard of the genoa track, opening up the slot.
If the wind comes forward of abeam, the genoa sheets lead will now be too far outboard. Ease the barber-hauler line and take up on the genoa sheet. This will pull the clew in to somewhere between the inboard and outboard positions, wherever the sail works best.
If the boat has a reaching strut, you can set it up on the leeward side of the mast and sheet the genoa through the jaw at the outboard end of the pole. This will get the jib clew farther outboard than the barber hauler will, opening up the slot even more. Another alternative is to sheet the genoa to the end of the main boom. However you do it, getting the headsails sheet lead outboard will improve your offwind performance. Ed Mapes