Anchor Alarm

This App will cover all you needs for a restful night in a bay!

What are the features?

Not just a clear structured design, but also other important features for a calm night in a bay are fulfilled with this app.

Not just circles

You can draw your own swing arc in shape of a triangle, a L or whatever you need.

Frei wählbarer Schwojenkreis

Awake guaranty

The alarm sounds rings you out of your bunk, even if you had one anchor beer too much.


Vessel size - true to scale

Define your vessel sizes, so you can see a true to scale drawing of your ship at map.

Schiffsmaße ändern

Battery check

The alarm can optinoally also ring if your battery get low and no power supply is connected.

Stromversorgung OK

GPS Accuracy

Also a bad GPS signal can trigger an alarm.

GPS Genauigkeit OK

And much more...

Wheter connecting a headset, or reducing the volume, all that can trigger an alarm. You can also disable each trigger individually.

Einzelne Alarme sind deaktivierbar


Exclusively on the App Store:

For iPhone and iPad only!


Further questions or any other queries?

Manual for Anchor Alarm

The idea behind "Anchor Alarm - A anchor watch for sailor and yachtsman" is to have the easiest and best app available for this use case. The handling is really not complicated, and descibed in this document step by step.

  1. Let go anchor!
  2. This is possible without app in besst seamanship.
  3. Open the app
  4. Open "Anchor Alarm - A anchor watch for sailor and yachtsman" and wait for a sufficient GPS fix.
  5. Adjust map view to your needs
  6. Tap the map icon on top left and first define the zoom level to your needs. The rings in the center map view show you the scale. Finally choose your favorite map style, I persoanly prefer in most cases the sattelite view.
  7. Configure your ship (optional)
  8. To show your ship in the map true to scale, you can enter the dimensions of your vessel. Tap on the vessel icon on top right and enter your dimensions either in meter or foot. Finally you can position your location on the vessel to show the finally correct position on the map. You will see later when you turn your iOS device, the vessel sketch on the map turns around this point. When you are done hit "< back".
  9. Draw the swing arc into the map
  10. Start drawing a circle around your ship. This is the allowed area to swing at anchor, when you leave this area after enabling the alarm, the alarm ring starts ringing. Of course you can draw shapes different to a circle, so just redraw the shape that fits best for you over the existing circle which will override the cisrcle with the new shape.
  11. Enable alarm
  12. Once the swing arc is defined ta on "anble alarm" to arm the alert. CAUTION: It is very likely the alarm sound will start ringing even if you did not leave your swing arc area. This is because there some other causes observed then just the position: Power supply > has the battery enough power? GPS accuracy > is the GPS signal good enough? Volume > Is the iPhone volume on the highest value? Headset > Is no headset connected that could avoid a alarm ring on the iPhone speaker? Which cause is the reason for the alarm is visible with the red highlighted text. You can disable each cause if you do not like the app to observe it (e.g. if you would like to have the volume not on the highest level, you can disable volume obervation). Now you can leave the app, a blue ribbon on top shows you the location service (and also anchor alarm) is still active.
  13. Disarm alarm
  14. When you would like to disable the alarm, just open the app and tap on "disarm", now you can leave the app and the blue ribbon will also disappear a second later.

Improve safety! (V1.10 or later)

Use the app in best case only when not charging, see below flow chart for some unlikely, but possible issues.

Flowchart of triggering an alarm

Privacy Policy

It is possible in the app to enter your email address, which is used for email notifications. So if you enter your email address, and an alarm is triggered, your email address is transferred at that time to m server, which send the email. I do not save the emailadress. Furthermore Open Street Map data is provided by my server, but I do not ask for any other personal information, or save such personal data from you.