Review of My Anchor Watch app for Android

A Useful Safety App When Used Correctly

My Anchor Watch app

My Anchor Watch is a reliable Android app to automatically notify you if your boat has drifted too far because the anchor is dragging. It is easy to use but has powerful features such as a definable GPS update frequency to help ensure the device's battery is not drained by constant use of the GPS.

Version reviewed: 3.1.3 free version
Requires Android 2.1 and up
Developer: Terboel
Available at Google Play Store (free) Pro version for $5.85
Tested on Lenovo A1 Tablet running Android 2.3

Key Features

The basic operation is simple:

  1. Ensure your device's GPS has a good fix on your position.
  2. Lower your anchor and tap the "Set Anchor" button (ideally with your GPS device near the anchor at the bow).
  3. Let out sufficient anchor rode (see How to Anchor).
  4. Determine what to set as your "maximum drift" (distance the boat moves from the anchor position before the alarm goes off). Typically this would be the amount of anchor rode you let out + the length of the boat (assuming you then take your GPS device back near the stern) + a safety factor to account for GPS accuracy (for example, 30 feet). Enter that maximum drift number into the app.
  5. Adjust other settings as desired. (Turn the volume up high to hear the alarm, turn the vibrator on or off, set the frequency of GPS updating, etc.)
  6. You're done. Now if the boat moves to a position outside the circle around the anchor defined by your maximum drift limit, the alarm will go off and continue to sound until you reset it.

    Additional features:

    • The app continues to run in the background if you want to want to use other functions or apps on your device.
    • The "Swing View" display provides all necessary visual data: the position of your anchor, a wide circle around it indicating the drift limit before the alarm sounds, and the position of your boat within the circle (with another circle indicating GPS accuracy). The four cardinal directions are indicated in this display, so that at any time you can see if your boat is swinging in a changed direction.
    • The "Details View" provides tabular information: anchor and boat position coordinates and the distance of the boat from the anchor and its direction in degrees. Both views also provide your setting for the drift limit and GPS updating frequency as well as GPS status and accuracy range.
    • You can set the GPS Update Period from every 2 seconds up through every 30 minutes. (The less often the device determines the GPS position, the slower will be battery use.)
    • In either view, tap "Check Drift" for an updated GPS position without having to wait for the next updating interval.
    • Other user-determined settings include use of feet or meters, longitude/latitude in degrees and minutes or degrees with decimals, and device shaking functions.

    The paid Pro version offers additional features that are useful when anchoring but may not be needed in many situations:

    • You can set anchor position "by projection" after the boat pulls back on the anchor rode.
    • You can set up an alarm sector within the drift circle to prevent drifting near other boats or shallows.
    • You can see a GPS track history.
    • You can filter out false alarms.
    • You can choose a different alarm sound.
    • You can set the device to send a text message or email in an alarm situation. I haven't tested this one yet, but it could be interesting, when you go ashore, to leave a smartphone with the app running there to message you on a different phone if your anchor starts dragging!

      Potential Downside

      It is essential to test the app thoroughly before entrusting the security of your boat and yourself to it when anchored for the night. Many different Android devices, and different versions of Android, have variations in the exact details of how they report GPS position to the app. On my test device, for example, if another GPS-reading app (like a chart navigation program) was running in the background, the GPS updating frequency within My Anchor Watch varied from how I set it there - different hardware settings also influenced the timing. Users of other devices may experience other small differences as well.

      Secondly, if you're trusting that the alarm will wake you if the anchor drags during the night, you need to ensure your device is positioned where it has a clear GPS signal (monitor its accuracy for a while after getting it set up) and that you do not let the battery run down.

      12-volt chargers are available for most Android devices, and I'd recommend using one and keeping the device plugged into the boat's power system even if you set the GPS to less frequent updating to save power - better safe than sorry.

      Finally, when setting the maximum drift for the alarm, think it through carefully. For example, if you tap the "Set Anchor" position from the cockpit when someone else at the bow lowers the anchor, you're starting off with a number off by the length of your boat. If the boat swings 180 degrees in the night, your GPS device would then be twice the boat length off from the assumed anchor position (plus the length of the anchor rode). In other words, the alarm could wake you in the middle of the night indicating your anchor had dragged when in actuality you had not marked the anchor's true position and you haven't dragged at all.

      Conclusions

      In my extensive testing, My Anchor Watch performed flawlessly and set off the alarm every time my device moved outside the swing circle limit, regardless of direction or speed of travel. It also set off the alarm if I moved my device to an area in the boat with a weaker GPS signal that decreased the position accuracy; I could then reset the alarm and reposition the device. I particularly appreciate that the alarm continues to ring until it's reset - no way I'd sleep through that! Of the various anchoring apps I've tested thus far, this one is my favorite and does a great job in the free version. Just remember that in most Android devices like smartphones, you may lose the GPS signal if you keep the device in your pocket. You might be used to keeping your phone on vibrate and trusting that, but putting the GPS in your pocket, especially down in the cabin, could lead to a fatal error if you turned off the audible alarm or lost the signal.

      DragQueen Anchor Alarm is another anchoring app available for both Android and Apple devices and smartphones.

      Other Boating Apps You Should Know:

      Best Sailing and Boating Apps
      5 Android Apps for Boat Charts and Navigation
      MarineCast Weather App for Boaters
      Little Sailor Sailing Simulator and Racing App

      Articles About Effective Anchoring:

      How to Anchor a Sailboat
      How to Use an Anchor Trip Line
      How to Retrieve an Anchor
      The Rocna Anchor vs the Classic CQR
      Use AnchorRescue to Prevent Losing a Fouled Anchor
      How to Choose an Anchor for Your Boat