Points of Sail - Running Downwind

Running Downwind

On this point of sail (also called running before the wind), the wind is coming from directly behind the boat. Running can be dangerous to those on board in the event of an accidental jibe.

When running, the mainsail is eased out as far as it will go. The jib will collapse because the mainsail blocks its wind, and must either be lowered and replaced by a spinnaker or set instead on the windward side of the boat. Running with the jib to windward is known as gull wing, goose wing, butterflying or wing and wing. In Scandinavian languages this is known as psalmbooking. A genoa gull-wings well, especially if stabilized by a whisker pole, which is similar to, but lighter than a spinnaker pole.

Racing sailboats typically set a spinnaker when sailing any point of sail from beam reach to a run. In 'non-extras' or 'no flying sails' class, where spinnakers are not permitted, poled-out genoas are often used when running downwind. In College and High School style racing, where neither spinnakers or poles are permitted, the jib is winged opposite the main and the boat heeled to windward to help maintain sail shape without a pole. Cruising yachtsmen, when running downwind, will often set either a poled-out genoa or a pole-less cruising 'chute (or gennaker). When running downwind for protracted periods, for example when ocean-crossing in steady trade winds, cruisers sometimes set twin poled-out jibs without a mainsail. All of these options are more stable and require less trimming effort than a spinnaker.

Steering can be difficult when running because there is less pressure on the tiller to provide feedback to the helmsman, and the boat is less stable, meaning the boat may more easily go off course than on other points of sail. This tendency to turn off course when running can be dangerous. If a boat turns to leeward too far, or sails "by the lee", the boat can jibe accidentally if the lee side of the sail catches the wind, causing the boom to swing across the boat quickly. A preventer can be used on yachts to help avoid this. Some boats, particularly smaller racing dinghies like the Laser, sail "by the lee" very well, but most sailboats should be careful to avoid this, and a vigilant helmsman is important.

Also when sailing on a dead downwind run an inexperienced or inattentive sailor can easily misjudge the real strength of the wind since the boat speed subtracts directly from the true wind speed and this makes the apparent wind less. In addition the sea conditions also falsely seem milder on this point of sail as developing white caps are shielded from view by the back of the waves and are less apparent. When changing course in a brisk wind from a run to a reach or a beat, a sailboat that seemed under control can instantly become over-canvassed and in danger of a sudden broach.