June 19th 2019

At 3 in the morning the anchor alarm went off again. But after checking the anchor itself and the coordinates of our position, it looked like we were still more or less in the same spot. Confusticate and bebother this dratted alarm! Whatever could be the reason for it to go off without reason? We were confident that it had to be false alarm, but it is not really pleasant to wake up to the sound of a diabolical alarm going off.
We tried to analyze what could have caused the alarm to go off. In the morning light we checked our position in relation to the shore. Judging by the visual reference points we hadn’t moved. If we had been dragging, it couldn’t have been much. So if we hadn’t been dragging what then? Our deduction was that it could have something to do with the timing of activating the anchor watch app. How the app works is that it uses GPS coordinates to mark the spot where you drop the anchor and then draw a circle -for example 25 meters in diameter- around that spot. Then you move back and let out anchor chain, depending on the depth, the current and the wind. You can see the position of the boat as a dot in the circle. So you can pivot around your anchor in all directions, as long as you stay within the circle all is well. If you start to drag and the dot representing the boat moves out of the circle, the alarm goes off. This works perfectly well if you activate the app at the exact moment you drop the anchor. But if you drop the anchor, move backwards to let out 20 meters of chain and then set the alarm, it draws a circle around the GPS coordinates of your boat, and not the anchor. With 20 meters of chain and a circle of 25 meters diameter the anchor would actually lie somewhere near to the edge of the circle. In this case the wind had shifted 45 degrees, causing the boat to pivot around the anchor and thus moving it out of the circle. We figured that this might have caused the alarm to go off, because when checking our gps coordinates and the visual reference points we were still at the same spot. Next time we should set the alarm at the moment we drop the anchor, or note the GPS coordinates, and not 5 minutes later.
You often read that you must develop a relationship of trust with your anchor. So we tried to relax and put faith in our anchor. It helped that the sun was shining because everything looks a lot better in the sun. We ended the day with the conclusion that we had set the anchor properly and made the right decision to stay. Enough reason to celebrate with a barbecue in the cockpit.










