Oscillating vs Persistent
The two shift types need opposite plans: in an oscillating breeze you tack on every header, but in a persistent shift you commit to one side and ride it up the whole leg.
Wind shifts come in two flavours and you have to know which you're in, because the right move for one is the wrong move for the other. An oscillating breeze swings back and forth around a mean, so you stay near the middle and tack each time you're headed to sail the shortest course. A persistent shift keeps rotating one way, so the smart boat digs out to the side the wind is going toward and gets lifted up the whole leg. Track your compass headings for a few minutes before the start: a swing-around-a-mean number is oscillating, a number that keeps marching one way is persistent.
Opens the animation on the boat-length grid — run it well, then brief it from the same picture. Free, no account needed.
What to call out
- Track your headings before committing, because a swing around a mean is oscillating but a heading that keeps marching one way is persistent — and they need opposite plans.
- In oscillating wind tack on the headers, because every header you sail through is distance lost and tacking keeps you on the shortest course.
- In a persistent shift dig into the header toward the new wind, because that side keeps gaining for the entire leg.
- Watch the trend for several minutes before you decide, because one reading can fool you into the wrong plan.