Last week, Core Instructor, Trevor Steel, discussed how wind direction becomes variable during SF Bay winters. The wind will not only shift generally during the season, say, from the South West to the North, but during your winter day of sailing, the wind will also shift moment to moment. Below is a description of the different types of wind shifts you can experience while sailing. While we teach these concepts in Basic Keelboat, it’s always good to revisit and review. Knowing how these different types of wind shifts affect your boat can greatly improve your skill and enjoyment of the sport.
When going upwind, a lift can be a great thing. A lift occurs when the wind shifts from your bow towards your stern. When on a close-hauled course, a lift allows you to do one of two things: head up with the shift or ease your sails and hold your course. If you are on a close-hauled course, we can assume your destination is straight upwind, so the typical reaction is to head up a few degrees with the shift.
When heading downwind, a lift can be a negative shift. When heading dead downwind, a lift will either force our boat to gybe, possible accidentally, or force our boat to head up away from our course. When sailing between a run and close-hauled, a lift will just require you to ease your sails – this assumes you are pointed towards your destination.
The opposite of a lift, a header occurs when the wind shifts towards your bow. When heading upwind, this is a negative event, as it will force you to bear away to accommodate for the new wind direction. Again, if you are sailing on a close-hauled course, we can assume your destination is straight upwind, a header will force you to steer at least several degrees away from your destination.
When heading downwind, though, a header can be a nice little gift from the wind gods. If our boat is sailing straight downwind and our wind shifts towards our bow, we now have the ability to sail an even deeper angle than before, which can potentially take us to our destination sooner. At the very least, a header will allow the dead downwind sailor to relax and not have to worry about an accidental gybe since he will now be sailing on a deep broad reach. When sailing anywhere between dead downwind and close-hauled, we can assume that our boat is pointing towards our destination, so trimming in the sails is all that’s needed with a header.
As you enjoy your winter sailing, pay attention to the wind shifts. When first playing with the nuances of wind shifts, one of the best tools is the wind indicator located at the top of the mast. Winter sailing is a great time to work on your ability to “sail the shifts.” Just as being able to handle a boat in the typical 20 knot SF Bay breeze qualifies you as a skipper, being able to quickly adjust course or sail trim for a wind shift is also a mark of a good sailor.