Staying secure at anchor is critical for peace of mind, especially overnight or in changing conditions. Savvy Navvy’s anchor alarm helps you monitor your position and alerts you if your boat starts to drift outside your set radius. In this guide, we’ll show you how to set up and use the anchor alarm so you can relax, knowing your boat is exactly where it should be.

Here's your checklist to ensure the anchor alarm functions properly:

• Keep your device on charge (recommended) or fully charged — GPS monitoring can quickly drain battery.
• Ensure your device has a clear view of the sky for accurate GPS positioning.
• Turn up the volume — make sure your device is not on silent, low volume, or Do Not Disturb mode.
• iPhone/iPad users: iOS respects the silent switch. Double-check your device is not in silent mode before turning in for the night.
• Keep the Savvy Navvy app running — closing the app will disable alarm monitoring.
• Leave your device on board — the alarm only works if your device stays with the vessel.

🎥 Prefer to watch instead of read? View a short video on how to use Savvy Navvy's Anchor Alarm here.

Enabling Your Anchor Alarm

1 - Go to the Anchor Alarm

When you've reached your destination and set anchor, you can activate the anchor alarm by selecting the Anchor Alarm entry from the main menu.

2 - Set up your Anchor Alarm

To set up your the anchor alarm in Savvy Navvy, start by setting the correct anchor position and defining your geofence safety zone.

• Your Location: Shown as a green arrow, determined by GPS from your device.
• Anchor Position: Your current vessel location is shown as a green arrow, and the anchor is marked with a blue anchor icon. Drag the anchor icon to where you physically dropped the anchor. The dotted line will show the distance between your vessel and the anchor to help guide accurate placement.
• Safety Zone (Outer Circle): This grey circle defines the maximum allowed distance your boat can move from the anchor. Set this radius to your chain length plus a margin for conditions like wind or tide shifts. To resize, drag the circular blue handle on the outer edge of the zone — the distance will update in real time.
• Swing Zone (Inner Circle): This is the expected area your boat will move within while at anchor, based on wind and tide. By default, the swing zone matches the safety zone, but you can customize it.

Customizing the Swing and Exclusion Zones

In some anchorages, you may want to restrict movement in a specific direction - for example, away from nearby rocks or obstructions.

To adjust this, drag the split handle (marked by a grey line) on the safety zone. This reveals three additional blue handles:

• One for resizing the swing zone
• Two for adjusting the size of the exclusion segment (the area between the swing zone and safety zone)
• You can rotate these segments by dragging the handles in a circular motion around the anchor

To close the exclusion segment and return to a uniform circle, drag the segment handles back together until they merge into a single handle.

3 - Activate Your Anchor Alarm

When you’re happy with your setup, tap Set alarm to arm the anchor alarm. The anchor icon and safety zone will turn green, indicating the alarm is active. If you change your mind, tap Cancel to exit without saving.

Once your Anchor Alarm is armed:

• A Disarm button appears in case you want to deactivate the alarm.
• A Settings icon allows you to edit the geofence zone at any time.
• A blue trackline will appear, showing how your vessel is moving in real time relative to the anchor — useful for monitoring swing and drift.
• If your vessel exits the safety zone, an audible alarm will sound. Use the Mute button to silence it for 5 minutes while you check your position. If it’s a false alarm, you may need to adjust the safety zone settings. If your anchor is dragging, re-anchor safely and reset the alarm at your new location.

When you want to leave the anchorage area disarm the alarm with the Disarm button and confirm that you want to Disarm alarm.

Updated on: 07/08/2025