The simplest, most complete and most robust anchor drag alarm. Trusted since 2013 for daily anchor watch by hundreds of sailors sleeping aboard.

Be alerted if your anchor drags with a simple yet full of features app : Easy to use - Late set - Remote mode - Dark mode support - Arc or circle Perimeter - Watch app - Find my boat

Press the main button (anchor down) to set anchor position,
Touch the alarm circle on map to adjust alarm radius and you're ready.

Press the main button (anchor up) disables all alarms.

Main button to set anchor at your current position,
Choose a position on the map: relocate anchor with drag and drop.

Either set a value in settings,
Or adjust it directly by touching the alarm circle.

ALL INCLUSIVE: No add, no subscription, no in app purchase add on.


Attention catching visual alarm with a blinking black/white screen (foreground only),
Accoustic with ringtone choice (iPads needs to be unmuted in the Control Center),

REMOTE MODE: check your position and get alerted on a second device.
FIND YOUR BOAT: dinghy option in remote mode

FIND MY BOAT: Crowded anchorage? The remote features a dinghy mode that will shows directions to your boat.

WORKS OFFLINE! You still see your boat position relative to the anchor, the anchor position and the alarm circle. Once offline the map is replaced by a graphic.

WATCH COMPANION APP : anchor, snooze and stop alarms from watch.
Watch notifications are less intrusive and will silence the phone notifications. We thus recommend to opt-out watch notifications.

The boat track is recorded and a time-colored path is displayed on map. You can identify at first glance whether your anchor position is drifting or not.

Enable, disable and reset the track. Export it in CSV or GPX format.

Vertical map scale in feet or meters.

User interface compatible with dark mode for night use.

Compatible with flic and flic V2 buttons, no hub required. flic buttons are splash proof smart buttons and you may use them as a remote to set, snooze and stop alarms.

Strictly respects your privacy: we do not collect any of your personal information, ever.

Compatible with external GPS for best accuracy (required for iPad with no gps) : tested on gns2000 , Dual xgps, Bad Elf and Garlmin glo.

Compatible with Flic buttons.

legal notice:

When the alarm is on, this app will use GPS in the background to be able to alert you. Continued use of GPS in the background can dramatically decrease battery life: don't forget your charger on board.

The remote mode uses an external server that could be shut down without notice by its provider or run slow . The remote mode needs data connexion and 2 apple or android devices

Use of the remote mode comes is subject to the agreement to this supplementary copyright notice:
In addition to the applicable standard EULA, permission is not granted to use Anchor! to track someone without his dedicated and recent consent.

Provided maps are not nautical charts.

What’s New

Version 6.20

Critical alerts

Ratings and Reviews

4.8 out of 5
55 Ratings

55 Ratings

Pan054 ,

Best anchor watch

This is the best anchor watch I was able to find. It does everything you'd expect it to do. Even when you switch off your ipad (not power-off or stopping the app of course), Anchor! stays active and will wake up itself (and you) on alarm conditions.
We've been using this app on our yacht in the Meds six months a year on an almost daily basis for a couple of years. It never was unreliable (apart from a small problem in a new version).
This review was written at 3 in the morning on an anchored yacht in 30 kts winds, gusting up to 42.

Pez333 ,

Great Anchor alarm

This alarm has saved my boat when we were hit by a strong southerly. The anchor dragged and then picked up seaweed. The alarm woke us up and I was on top of it.
Easy to use with good coverage. Just set the pick and the alarm and it works with IPhone or my iPad. I leave it by the bed charging and it monitors all night. You can also set it to call you by sms if you leave the boat with iPad monitoring while you go out on your tender for a black walk. 10/10

Developer Response ,

Thanks a lot this great review :)
A precision, the remote mode needs data coverage and is not based on SMS.

TheTikiTikiTiki ,

Great App

Great app - used this nightly during a bareboat charter in the Whitsundays Queensland. Often didn’t have any mobile reception so couldn’t load background maps, but for the purposes of alarming if drifting beyond a radius this app was perfect. Great that it keeps running with phone screen off. Was always interesting to review the app in the morning to see how the boat had moved around during the night.

App Privacy

The developer, Pomacanthus, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer's privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members will be able to use this app with Family Sharing enabled.

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