Anchor Alarm

Our Furuno chart plotter has an anchor watch feature that you can set in the cockpit and at the nav station independently of each other. What's nice is that it draws a diameter of the limit you set. That way, you don't have to guess what to set it to. Our first night at anchor, we set .010nm (60ft). The anchor alarm went off in the middle of the night and we woke up, flashed the spotlight and tried to determine if we were dragging. The location indicator for the boat was hovering near the edge of our swing radius. After deciding that we were not dragging, and that our swing radius was set too small, we decided to set the anchor watch to .020nm (121 ft). Below are our anchor alarm circles for 2 different nights. The red marks inside the circle are our tracks from swinging at anchor.