While at anchor in a coastal cove, how can the skipper quickly and reliably verify whether the vessel is holding or dragging anchor (garreando)?

1. By establishing visual transit bearings (enfilaciones) to fixed landmarks ashore, checking the GPS anchor watch alarm, and feeling for chain vibration/snubbing
2. By observing if the vessel swings with the tidal current
3. By checking if the bilge pump is operating intermittently
4. By measuring the sea surface water temperature every 15 minutes