Anchor alarms....

[pandos]

Interesting replies. Never tried an app.. and never dawned on me that I could alter center point of the allowable swing to the anchor position, on the plotter..

All makes sense now.. like the idea of a tracker which would send sms

 

[duncan99210]

I use the Anchor app on an iPhone. Very easy to set using the scope and direction of the boat. I don’t use the plotter, the alarm is too quiet and it uses too much power. iPhone by my bunk does the job. I’ve never bothered with trying to set the thing with an accuracy of much better than +/- about 10m: if that’s likely to see me hitting another boat or the shore, I’ve picked the wrong place to stop.
Earlier alarm apps didn’t average enough fixes to stop frequent false alarms: Anchor seems to have solved this problem and I haven’t had a false alarm from the app yet. Had alarms when I’ve not set the anchor position properly but no true false alarms.

 

[differentroads]

I use the Anchor app on an iPhone. .... Anchor seems to have solved this problem and I haven’t had a false alarm from the app yet. Had alarms when I’ve not set the anchor position properly but no true false alarms.

I use Anchor Pro on Android and can second your experience that good anchor watch apps work well in practice, despite the potential limitations of the technology. And like any half decent seaman, I use the electronic alarm only as an aid to keeping anchor watch. In tricky conditions I take compass bearings, plot escape routes and wake up from time to time to eyeball the situation.

 

[pandos]

Thanks for replies . Will check my plotter to see if the anchor position can be set manually.

I never thought of an app.

I like the idea of a tracker that can send SMS..

 

[RupertW]

Thanks for replies . Will check my plotter to see if the anchor position can be set manually.

I never thought of an app.

I like the idea of a tracker that can send SMS..

I moved over to an app once I realised that charging the phone took less than keeping instruments on and liked having boat position graphically available by my pillow

 

[Roberto]

I quite like the "YAPP" anchor alarm by forumite Angus: it is connected to Seatalk/Nmea and can be parametred to trigger an alarm if gps position drift, depth, wind speed, wind direction etc go beyond set limits.

 

[LittleSister]

Now if we consider that the best charts are made using DGPS, we should add another 2 to 3m of uncertainty to our swing radius to allow for chart inaccuracy,

What have charts got to do with it?

(p.s. Don't bank on charts being within 2 to 3m of reality!)

 

[Neeves]

We seldom set an anchor alarm, we find our anchor reliable. Alarms are fine but if you want to climb a hill and it takes all day - then an alarm is really not much use - you need to have a reliable anchor (and be confident in your technique and choice of anchorage). There would not be much point in sailing to many of the places people desire - if you are tied to your yacht and cannot leave it for a decent period of time and explore the hinterland. We are unlikely to climb a 750m high hill if a front is forecast - not because we don't trust the kit but hill climbing with a front seldom has the pleasure of choosing a more conducive day.

We used to use our chart plotter (with an offset facility for the anchor position) but once we had grown confidence in both the anchor, the ancillary kit and our ability to judge the anchorage we no longer bother.

The major problem with chart plotter (or instrument derived alarms) - you need a decent battery bank - unless you have a big solar array, windgen, generator or willing to run your engines (which is a bit contradictory if you are in quiet anchorage). Anchor alarms are also unobtrusive (and even more so if your instruments are at the helm and your berth in the bow). We wired in a piezo electric alarm, and if you are sleeping so lightly to hear a normal alarm - you may as well get up and have a look.

We have a compass at the foot of our berth as though we are confident in our anchoring we are less confident in detecting from the berth a wind (and less important - tide) shift. We often sail on wind shifts (when fronts pass through) and seeing the change in the lie of the catamaran can be quickly seen and confirmed.

 

[Crinan12]

We seldom set an anchor alarm, we find our anchor reliable. Alarms are fine but if you want to climb a hill and it takes all day - then an alarm is really not much use - you need to have a reliable anchor (and be confident in your technique and choice of anchorage). There would not be much point in sailing to many of the places people desire - if you are tied to your yacht and cannot leave it for a decent period of time and explore the hinterland. We are unlikely to climb a 1,500m high hill if a front is forecast - not because we don't trust the kit but hill climbing with a front seldom has the pleasure of choosing a more conducive day.

We used to use our chart plotter (with an offset facility for the anchor position) but once we had grown confidence in both the anchor, the ancillary kit and our ability to judge the anchorage we no longer bother.

The major problem with chart plotter (or instrument derived alarms) - you need a decent battery bank - unless you have a big solar array, windgen, generator or willing to run your engines (which is a bit contradictory if you are in quiet anchorage). Anchor alarms are also unobtrusive (and even more so if your instruments are at the helm and your berth in the bow). We wired in a piezo electric alarm, and if you are sleeping so lightly to hear a normal alarm - you may as well get up and have a look.

We have a compass at the foot of our berth as though we are confident in our anchoring we are less confident in detecting from the berth a wind (and less important - tide) shift. We often sail on wind shifts (when fronts pass through) and seeing the change in the lie of the catamaran can be quickly seen and confirmed.

Is it not worth setting an alarm on your phone anyway thou, even just for sleeping ? It only takes a couple seconds.
Surely a good wee back up thing even if you think you'll never need it ?
Cheers

 

[Neeves]

In many parts of Tasmania, and the Australian coast, there is no mobile coverage. There is little point in keeping mobile charged up for only an anchor watch. If we are twitchy we would use the chart plotter - as if the conditions become questionable we would want to find better shelter - and having the chart plotter on means we do not need to wait for it to boot up. This would be quite exceptional.

As I said if we need an anchor alarm - we cannot climb Mount Misery nor Mount Rugby - why make the effort to sail over 1,000nm (each way) if you need to rely on an anchor alarm 24/7.

I don't quite have NormanS' confidence of leaving our catamaran for a month - but we subscribe to his doctrine.

Jonathan

 

[Crinan12]

In many parts of Tasmania, and the Australian coast, there is no mobile coverage. There is little point in keeping mobile charged up for only an anchor watch. If we are twitchy we would use the chart plotter - as if the conditions become questionable we would want to find better shelter - and having the chart plotter on means we do not need to wait for it to boot up. This would be quite exceptional.

As I said if we need an anchor alarm - we cannot climb Mount Misery nor Mount Rugby - why make the effort to sail over 1,000nm (each way) if you need to rely on an anchor alarm 24/7.

I don't quite have NormanS' confidence of leaving our catamaran for a month - but we subscribe to his doctrine.

Jonathan

Fair enough Jonathan I've only anchored once so can't say too much and you're the anchoring expert ! But I would have thought that if something went wrong in the middle of the night when sleeping a loud alarm could only be a good thing

from messing about with the app my understanding is that it doesn't need phone signal unless you want it to text you (uses GPS) and uses very little battery. I never turn my phone off anyway. Going to mess about with the app this summer and see how I get on
cheers

 

[Dutch01527]

We use the anchor app "anchor".
When you deploy the anchor then set your watch on the phone, I move the position of the anchor forward to an estimated position of the anchor.
Then the boat swings around the anchor in its approximate position

Another vote for the ”anchor” app. It has the added advantage of being able link It to a second device. Means that you can set the alarm on a tablet and leave that on the boat and retire to the pub ashore. You can receive alarms and view a copy of the track on a phone you take with you. Very clever.

 

[Refueler]

Anything to do with anchors and it always ends up a two camp matter !!

 

[sailaboutvic]

Has many may know we spend more night at anchor then any thing else and although we very confident in the way we anchor and our gear we still set an anchor alarm on our phone which is kept just by our bed just in case as things can and do go wrong .
As already said ours work on GPS and don't need a phone signal .
We don't keep the radius as tight as some here like to do unless we in a very tight spot .
We set ours has we drop the anchor , it's set from the cockpit so being a CC boat we aloud for the scope plus 20 mts 10 to aloud for the different from the cockpit to the bow and 10 mts extra to give some leeway for any GPS unaccuracy between the phone and GPS and so it doesn't goes off by mistake .
This works for us fine although I seen to wake up anyway if the pick picks up or the boat moves in a strangers way .

 

[Refueler]

Someone mentioned a tracker ..... and sending an SMS ...

Fine - except for one thing ..... they only provide a position on request ... they are not an alarm ...

We use them a lot on RC models so we can find them if they go down 'unexpectedly' ..

AND many actually do not give you as accurate a position as a plotter .... and why they often have a BEEPER as well ... so the position is roughly where it is ... the BEEPER then used to actually find it.

Here's a common one used :

RF-V16

https://uk.gearbest.com/car-gps-tracking/pp_232609.html

There are others more expensive such as Trackimo ... Marco Polo etc.

But as a user of such - I don't really think they are much use for anchor alarms !! But possibly useful if boat really goes a wandering ... or stolen ?

 

[GHA]

Is it not worth setting an alarm on your phone anyway thou, even just for sleeping ? It only takes a couple seconds.
Surely a good wee back up thing even if you think you'll never need it ?
Cheers

Lots of people do, no downside really. mA of current draw, anchor pro is an excellent app, sits quietly keeping an eye on things for you. Easy to spot wind shifts & you can set various zones shapes, anchor history can come in handy as well.

But this being a web forum you get all sorts of entrenched viewpoints often based just on some weird opinions rather than open minded experience.
Give anchor app a go and make your own mind up, no downsides

 

[bluerm166]

Not sure if anyone above has mentioned the Open CPN alarm which I find excellent.It does exactly what the OP describes.You can simply shift the circle centre or change the radius +- later on when you see the pattern.

 

[Neeves]

Crinan,

I'm no anchor nor anchoring expert -but forecasts can be wrong and you are as likely to drag at noon as at midnight. If you are on the top of a hill and its taken you 6 hours to get there - then no anchor alarm is going to help you. You need reliable kit or you are prisoner of your yacht. Our catamaran is a means to get to hills you can climb (thats a bit grand) - walk (strenuous) up. Its as close to being like Scotland as you can get (apart from the black swans nd the eels). If we rely on the anchoring kit for a 12 hour walk up Mount Rugby - we can rely on the same kit when we sleep.

But don't do as I do, do as i say - which was not what the OP wanted - he, presumably wanted to know what as individuals we do. If an anchor alarm or an app makes anyone feel more comfortable - use it.

As GHA says - try it make up your own mind - just remember when you are the top of that Munro - you rely on the kit, not the app.

Jonathan

 

[noelex]

I would advocate selecting the best anchoring gear as the most important priority, but if you anchor often enough an anchor alarm, sooner or later, will prove to be worthwhile. Don’t believe the stories that anchoring is 100% secure.

The phone apps are great. One tip is to consider a Bluetooth GPS reciever (we use a Garmin GLO). This can be placed where it will recieve the best GPS signal relaying this to all the tablets phones etc on board. An accurate GPS position is essential for the anchor alarm to work well especially to detect the anchor slowly slipping backwards which is often a precursor to to anchor breaking out completely. The GPS in phones and tablets will still acquire a valid position in enclosed spaces such as bedroom but the position accuracy diminishes.

When away from the boat the apps that send a email or text message if you drift outside the circle can be useful. The other option If you want to keep an eye on your boat while at the pub is to use AIS. You can zoom in on one of the many AIS apps on your phone or tablet such as Marine Traffic and see a nice arc of exactly your boats position. This allows wind-shifts as well as position to be monitored. One advantage of this option is you can keep a similar eye on other boats in the anchorage (I am more worried about other boats dragging). This obviously only works for boats with an AIS transmitter, but this is becoming common on cruising boats and more and more seem to be transmitting their position at anchor.

 

[Crinan12]

Sorry yeah I'm just talking about when on or in sight of the boat I suppose
And yeah I get that you can drag anytime - it's just at night it's surely a different ball game entirely because, well, you're asleep -and to my mind that's where the alarm could be a lifesaver
Cheers