"Other drag alarm apps have not been successful and my Garmin GPS is hard to set and has proved unreliable. Your app certainly gets my vote! … We had 20+ kts of wind and rising when the alarm went off. Spotted we were dragging at an alarming speed towards the South breakwater at Portimao, managed to start engine and get to safety but I think without the app we would have hit it or run aground near it. So extra special thanks for producing such an excellent app that works so well."- Nigel Heaton
"Saved my bacon! I used this app sailing in the San Juans last summer. I am a fairly novice and paranoid sailor, but using this app allowed us to have an amazing week. Using this app we were able to anchor in some very tight conditions in weather. There was one night where the app detected us dragging the anchor in a tight anchorage with other boats. Without this app, our sailing trip would have: a) not been possible, or b) been disastrous. Thanks to the folks that developed smart phones and apps!" - Erik Gerking
"Must have for cruisers! You must have this if you anchor your boat and can't stay on deck to be sure you stay put. Sleep soundly or go ashore for the day and know the boat is where you put it." - Daniel Otte
"Remarkable, The most realistic and effective app on Android" - Pierre Lavergne
What is Anchor Alert?
Anchor Alert is an advanced anchor alarm application from SlimJiM Software developed exclusively for Android. Anchor Alert was the first anchor alarm available for Android and still leads the rest in terms of features and reliability.
It features point and click anchor projection using the phone's built-in GPS and compass and allows setting of an exclusion area and optional slack zone. Together with the audible and haptic (vibration) alerts and support for running as a background task which allows the phone's GPS to sleep to save power, Anchor Alert is the world's most advanced smart-phone based anchor alarm.
Anchor Alert is only available on the Google Play store.
Read on to learn about some of the advanced features of this application and some of the other uses it can be put to…
Please note: Due to the use of some advanced functions only available in newer releases of Android, Anchor Alert is not available for versions earlier than 4.0. If you are stuck on an older version of Android and wish to use Anchor Alert you should contact your carrier about an upgrade.
Unlike other anchor alarms, Anchor Alert allows you to project an anchor position in any direction and by any distance you want by simple point and click.
Anchor Alert uses Android's magnetic declination tables to automatically correct the phone's built-in compass for local magnetic differences so that an accurate anchor position can be calculated at any time and at any position on the globe. These magnetic declination tables are updated as required with the Android system so they will always remain as up to date as your phone.
Anchor Alert allows any sector of the anchor circle to be excluded from the allowed swing area and if your vessel drifts into it, an alarm will be triggered.
This may be useful when you find the need to anchor your vessel close to land for more protection, close to another vessel that is moored to a buoy, or when anchored in a steady wind and you want to know when the wind changes. The exclusion area can be input with precision from the application preferences or with ease by touch and drag accessible by long-pressing on the centre of the screen.
You may also find at times that you wish to define a slack zone within the exclusion area. For example, when anchored in a bay where the vessel might swing around 180 degrees from it's original position due to tidal changes but you may only wish to be alerted if the anchor is likely to drag and not when the vessel has just wandered over the anchor position at slack tide. Anchor Alert allows this too. By setting the Slack Zone option and independently changing both the distance to anchor and the drift distance, any size slack area may be set around the anchor position.
Anchor Alert also has a night mode that dims the screen and changes the colour scheme so you don't lose your night vision.
Anchor Alert is designed to take full advantage of Android's multi-tasking ability. It is capable of monitoring the anchor position while running as a background task and allows you to use your device for other things such as checking your email or taking a call. No other smart-phone based anchor alarm can do that!
Prefer to use feet? Or do you work better with the metric system?
No problem. Anchor Alert supports both metric and imperial measurements, just select your preference from the menu and it's all taken care of.
Anchor Alert supports audio and vibration alert options and a visible alert dialog is also displayed through which you can cancel or snooze the alarm for a period that you define.
Anchor Alert can also inform you if your battery is getting low. By selecting the low battery alert in the application settings a visual notification with optional audio and vibration alerts will be triggered to alert you that the battery is running down. Once at 15% power, then again at 10% and at every change from 5% and below.
Anchor Alert takes your security and privacy seriously too, the location data used in historic traces is relative to the anchor point only and no personal data whatsoever is collected or stored.
Anchor Alert has always had the option to send SMS alerts, but because of a Google policy change a few years ago it had to be disabled. It may be re-enabled but requires side-loading an enabler app and installing from the beta channel.
First un-install any existing version of Anchor Alert from your device, then visit the Google Play store page and join the beta (you can do this by opening the play app and searching for Anchor Alert, there should be a 'join the beta' section, click join and follow the instructions). Once you have installed the beta version but before you launch it you will need to manually install this SMS enabler app.
You will need to allow installing from unknown sources but you can disable this again after you have installed the enabler. You may get a Play Protect warning dialog saying that the app was built for an earlier version, this is how we get around the SMS permissions block. If you see this, expand the "More details" section and press "Install anyway". Once you have installed the SMS enabler, open Anchor Alert and you should now see the SMS functions in the settings.
As of Android 15, Google have seen fit to add even more hoops to jump through. If you see the 'App was denied access to SMS' dialog and cannot enable the SMS you will need to do the following:
The SMS enabler by itself does nothing more than request SMS permissions on behalf of Anchor Alert, this is why it needs to be side-loaded. You will need to keep the SMS enabler installed to use SMS features.
Once SMS functions have been restored and a designated number to receive SMS alerts is defined, Anchor Alert will also respond to certain messages from the designated number:
The reason it needed to be done this way is that Google decided a few years ago to prevent Play store apps from requesting SMS permissions unless the were the default SMS provider*, so the SMS alerts feature had to be disabled. The code to handle SMS is still there however and just needs reactivating, but what this means is that a setting had to be introduced into the app that would have broken updates for all existing users, so instead of forcing everyone to re-install, it was decided that the Beta channel would be used for this purpose. The software is otherwise exactly the same, receives all the same updates and is in no way Beta quality.
* The default SMS provider is the default app you use for sending and receiving SMS. Obviously an anchor alert app that sends SMS alerts when a vessel is out of range does not meet this criteria, nor would I want it to. Although there was an exemption process and I did attempt many times to get Anchor Alert approved, after receiving the same canned messages back from Google's app review process time-and-time-again I lost any faith that a human was reviewing the application and simply removed the permission entirely so as to pass the automated review process.
Set the exclusion area start position to 190 degrees and set the scope to 340, set the anchor position to however far away your target is, say 30,000 metres (30kM) or 100,000 feet (19 miles), from your current position, point the phone in the direction you wish to travel and press OK to set anchor. You can then use Anchor Alert as a guide to your location, stray too far off course and you'll get an alert, the alert area also gets smaller the closer you get to your desired location (the anchor position) so you need never be too far off course. Make sure anchor tracking is enabled too and let Anchor Alert guide you both magnetically and by your phone's GPS.
Before going walkabout in an unfamiliar location, and after safely mooring your boat of course, set the anchor distance to 0 and anchor your phone at it's current position, the anchor will now be your point of reference. Now set the drift distance to the area you wish to cover, make sure Anchor Tracking is on in the preferences and take the phone with you. Anchor Alert will show you in which direction and how far away your anchored location is and can guide you back, useful if you often forget where you left your boat / car / significant other!
Anchor Alert comes with a built-in user guide and help section accessible from the main menu, you will also receive free technical support by email for the life of your purchase. See About SlimJiM for contact details.
Anchor Alert is under active development, when you buy you will automatically receive all upgrades as soon as they are released and at zero extra cost. You will also have the chance to participate in the development of Anchor Alert and have your say as to what features should be integrated in future releases, an example of which is the night-mode feature that was added in version 1.3.2 in response to a user request. Although there is no guarantee that all such feature requests can or will be implemented, where possible a detailed rationale for the decision to include or exclude a feature will usually be given, now we can't say fairer than that!
SlimJiM Software is the alias of Simon Morgan, a software developer with over 2 decades of industry experience in Java and Open Source technologies. Simon is also a RYA/MCA certified Yachtmaster and PADI Dive Instructor.
Do you have a great software idea but are unsure how to implement it? SlimJiM Software may be able to help. Contact SlimJiM to find out what can be done for you.
Please direct all queries to [email protected]
You can view our privacy policy here.
