We’ve heard of stalling a car and airplane, but what is stalling a sailboat and how do you prevent or recover from it?
Before we can discuss how to prevent and recover from a stall, we must first understand what a stall is. A sailboat creates lift due to the difference of pressures on the front and back of its sails and keel, picture a sailboat as an airplane turned sideways with the keel and sails being the wings. To create lift you first must have speed (the airplane rolling down the runway) and the same goes for a sailboat.
When you try to “lift” the sailboat (sail close hauled or above) without first having speed, the boat will slow and start drifting sideways – this is a stall. We commonly see this on the Capri 22’s due to their sensitivity and smaller “wings”. The skipper pulls the mainsheet on hard, turns the tiller to point the boat upwind, and yet the boat keeps going sideways, despite the tiller being hard over…classic stall.
So, you find yourself in the above situation – what do you do to recover from the stall and get the boat sailing again? Well, going back to physics, you must have speed before you can have lift. Turn the boat away from the wind, ease the sails slightly, and get your boat moving again. Once you have reached speed, you can once again sail higher into the wind on a close-hauled course. The physics of lift begin to diminish the lower you sail, so turning the boat away from the wind builds speed the fastest, much like an airplane putting the nose down to recover from a stall.
Most every sailor has stalled a boat, whether they realize it or not, so let’s go over some ways to keep yourself out of a stalled situation. As we know, you can’t have lift without having speed; When the boat is moving slow, remember, you cannot sail at close-hauled or above without first building speed. We can also trim our sails in a manner to prevent stalling at slow speeds. Easing the sails on a slow-moving boat does two things – one, it creates a “fuller” surface, that is more conducive to boat speed in light wind, and two, it forces the driver to stay out of the no sail zone, or close-hauled. A loosely trimmed sail will luff as you approach close-hauled, and the driver will know to turn the boat down a bit to keep it moving.