Wind on the chart

Wind decides a lake day. It decides which shore is workable, whether a canopy goes on this afternoon or tomorrow, and which way the barge drifts while the crew sets a lift. So it is on the chart: a small arrow and a number in the status strip, and the same chip beside the dispatch map in the office.

Reading it

On the chart it is a bold arrow and a number: the speed in miles per hour. When the gusts run well above the steady wind, three short streaks light up beside it — one for a quarter over, two for half over, all three for double, amber through red. Press and hold the chip (or read it out) for the sentence — 12 mph from the NW, gusts 20. Beside the dispatch map the sentence is written out. The arrow points the way the wind is going, which is what a flag on a dock shows and what you read off the water. Under a mile an hour it just says Calm.

Following the boat

While the chart is following the boat — north-up or heading-up — the arrow is drawn relative to the boat's course, like the wind instrument at a helm: straight up is dead ahead, and the arrow shows where the wind is blowing across the bow. Turn the boat and the arrow turns with it. With the chart parked, the arrow is drawn relative to the chart instead, so it stays true over the water you are looking at.

Where it comes from

Weather data by Open-Meteo.com, read for the point the chart is centered on. The source updates every fifteen minutes and the chart checks every five, and again whenever the boat moves about a kilometre, so a new reading is on the water within minutes of existing. Tap the chip for the detail: the sentence, the gusts, what the meter means, and when the source read it, in your phone's own clock. On the dispatch map it is read at the center of the lake the day is on. When there is no reading — no signal, or the source is down — the chip disappears rather than showing a stale number. It is a reading, not a forecast, and it is not a substitute for looking at the water.