Currently, we use boundary circles for this. Create a boundary circle with the center where you dropped anchor and the radius to something sensible depending on your scope and rode length, etc., then set of the off-limits property to outside. If your vessel drifts outside the circle you will get an alarm. You can also configure a “Screen” to automatically drop a pre-configured boundary circle at the vessels current location, which you switch to that screen. This video covers the topic: