Anchorwatch — an anchor watch that models the swing

Field notes

The app builds its monitoring boundary from entered depth, chain length, GPS-to-bow distance, and a safety margin rather than treating the boat as a point inside a generic radius. Its described workflow combines GPS-scatter filtering with post-set tracking, Open-Meteo wind and wave forecasts, and OpenSeaMap chart notes. Phone sirens, Apple Watch haptics, and a lock-screen Live Activity extend the alert surface, while the page says operational data remains on the devices.