Now imagine the opposite. A lull, with a constant TWD, causes the boat to sit more upright, meaning it wants to fall away from the wind. Here, the AWA suddenly narrows, causing both the main and headsail to luff. We say that angle of incidence is too narrow. Recall that when that happens to a plane, lift decreases and drag increases—meaning it could drop from the sky. A boat slows. In both cases it’s because lift decreased relative to drag. Now, the helmsman has to steer up. Best case is a narrower rudder angle and lower lift relative to drag. Worse case is the rudder is actually pointing to leeward. The boat will be out of balance, with the direct result being a loss of VMG, caused by increased leeway and less lift from the sail plan and rudder.