The no-go zone is the range of directions, roughly 45 degrees either side of the wind, in which a sailing boat can’t sail. Pointed into it, the sails flap instead of filling, and the boat slows down and stops.
No sailing boat can sail straight into the wind. For about 45 degrees either side of the direction the wind is coming from, about 90 degrees in all, the sails can’t take up their curved, wing-like shape. They flap like a flag, produce no drive, and the boat slows down and eventually stops. This range of headings is the no-go zone.
How wide it is depends on the boat. A well-sailed racing yacht with good sails might sail at about 35 degrees to the true wind, and an older cruising boat might manage only 50. For most purposes, 45 degrees is a good figure to remember.
You can find the edge of it on the water. Sailing with the sails pulled in tight, head up slowly towards the wind. The front of the jib starts to lift and flutter, and the windward telltales lift: you have reached the edge of the no-go zone. Bear away a few degrees until the sails fill and the telltales stream again, and you are close-hauled.
Getting to a place directly upwind, inside the no-go zone, means sailing a zigzag: close-hauled on one tack, then turning through the wind and sailing close-hauled on the other. This is called beating, and each turn is a tack.
Two things to watch:
- Don’t steer a few degrees into the no-go zone to save distance. This is called pinching: the boat slows and slips sideways more, and ends up no higher than if she had sailed at full speed.
- If the boat stops while pointing into the no-go zone, for example in a slow tack, she is in irons and can’t be steered until she gathers way again.
The no-go zone is also useful: heading into it deliberately is how you slow down and stop, for example when picking up a mooring.
More in the book: Chapter 4, Points of sail