Navionics-am i missing something?

[Boathook]

Ok,but in all the years I have only had an anchor drag 3 times (Greece..Dokos, weed and poor holding, Aegina, poor holding and anchor dropped off shelf into deep water...Poros, storm came through 70 kts wind..)

How do you determine an accurate ring guard when your anchor trips and needs to reset? OK you can do a calculated guess but that won't be any different than you suggesting a car system didn't offer the level of accuracy.
My point being if there isn't a reliable simple system on offer from the marine electronics...go down the car route they are certainly accurate enough within the guess work ranges.

Like you my anchor has only dragged a few times and the places I seem to anchor I will be either aground or hitting other boats before the alarm goes off. I try to avoid crowded places but on the south coast this isn't easy unless in an exposed anchorage !

 

[Bristolfashion]

There is a lot of angst in this thread: not having anchor watch Apps, not trusting anchor watch Apps, having to test the anchor watch App, worried about setting up the anchor watch App. You don't need an App, just anchor, check it is holding and enjoy your time at anchor.

Put the small boy on deck to peer at the transits!

 

[Mark-1]

There is a lot of angst in this thread: not having anchor watch Apps, not trusting anchor watch Apps, having to test the anchor watch App, worried about setting up the anchor watch App. You don't need an App, just anchor, check it is holding and enjoy your time at anchor.

I suspect from the average age of forumites that the vast majority of all our anchoring took place long before smartphones were dreamed of.

I'd be amazing if anyone on this thread thought anchor apps were anything more than a "nice to have".

 

[Boathook]

I suspect from the average age of forumites that the vast majority of all our anchoring took place long before smartphones were dreamed of.

I'd be amazing if anyone on this thread thought anchor apps were anything more than a "nice to have".

I've never thought about an anchor app and after this thread still can't visualising using one.

 

[[193211]]

Another vote for Anchor Pro.

 

[B27]

I suspect from the average age of forumites that the vast majority of all our anchoring took place long before smartphones were dreamed of.

I'd be amazing if anyone on this thread thought anchor apps were anything more than a "nice to have".

Was it last year or the year before, anchored boat went up the beach at Penzance?
Would an anchor alarm have helped there?

Personally, the anchor alarm on my phone has been great.
Not for preventing calamity, but just as a nice little tool which helps me understand how well my anchor works.
When you're anchored in plenty of space it's great for telling if you're dragging a bit.

It's also handy as a simple app that fires up quickly and tells me my lat and long in nice big numbers.

 

[noelex]

How do you determine an accurate ring guard when your anchor trips and needs to reset?

If the anchor alarm is set correctly with the centre point over the anchor, the alarm will not be triggered by moving around the swing circle, although it is occasionally useful to deliberately set an anchor alarm that will alert you to a change in wind direction.

The guard zone should be the length of the rode, plus the distance between the GPS antenna and the bow, plus a small distance to allow for errors in the GPS or anchor position.

A correctly set alarm will only be triggered if the anchor moves. If my anchor ever moves I want to be woken up.

 

[Bristolfashion]

Yes, the "advanced" facility to set the anchor position a known distance & bearing from current point is what we use - much easier than trying to press the thing exactly on the anchor drop.

We leave the GPS track on for a bit to see if we're slipping. If it looks like Trump's hair*, you're good to go.

* Note to mods, this is a physical description, not a political comment. A pileus cloud shape if you prefer.

 

[dunedin]

I find it amazing that after investing a significant amount of money in a GPS navigation aid, the consesus appears from this forum, a downloaded 3rd party app on a mobile phone is more efficient for something as basic as anchoring.

I do not want to loose focus of my surroundings when anchoring by looking and filling out details on a 'wizard'. However if I later decide to stay the night or go below, I want to set an alarm.

Can it be so dificult for a state of the art piece of marine electronics to allow me to tap the screen and tell it where i know i put my anchor and then set that as the centre of my swing radius.

Anchor lite / pro, and may other apps can do it.

Am i missing something? Or can an anchor position on an Axiom 9 only be set using their Wizard?

I have no idea if my main chart plotter has an anchor alarm function or not. It and the other sensors get switched off as soon as anchored for the night. The anchor alarm on a phone or tablet uses much less battery power, and can be beside skippers bunk, so better for this job.

 

[Bristolfashion]

I have no idea if my main chart plotter has an anchor alarm function or not. It and the other sensors get switched off as soon as anchored for the night. The anchor alarm on a phone or tablet uses much less battery power, and can be beside skippers bunk, so better for this job.

I like knowing it's there - the other advantage, which we have used once or twice is that the depth alarm works if the instruments are on.

 

[B27]

If the anchor alarm is set correctly with the centre point over the anchor, the alarm will not be triggered by moving around the swing circle, although it is occasionally useful to deliberately set an anchor alarm that will alert you to a change in wind direction.

The guard zone should be the length of the rode, plus the distance between the GPS antenna and the bow, plus a small distance to allow for errors in the GPS or anchor position.

A correctly set alarm will only be triggered if the anchor moves. If my anchor ever moves I want to be woken up.

I tend to add a few metres to allow the anchor to move a bit if the tide turns.
I guess if the anchorage was really crowded and there wasn't space for that, I'd want to be awake when the tide turns anyway!

TBH, I'd rather pay for a mooring than be in an overcrowded anchorage.

 

[noelex]

If the wind alters direction slowly and the breadcrumb trace remains the same distance from the guard zone, as in the example below, it is an indication that the alarm is correctly centred over the anchor.

An alarm that is correctly set like this can alert you to even quite small movements of the anchor without any false alarms even when the wind direction changes significantly.

 

[Bristolfashion]

If the wind alters direction slowly and the breadcrumb trace remains the same distance from the guard zone, as in the example below, it is an indication that the alarm is correctly centred over the anchor.

An alarm that is correctly set like this can alert you to even quite small movements of the anchor.

View attachment 180391

You're a lot more precise than I am! I'm more "will I hit anything expensive"‽

 

[Mark-1]

You're a lot more precise than I am! I'm more "will I hit anything expensive"‽

...or embarrassing.

 

[billskip]

If the anchor alarm is set correctly with the centre point over the anchor, the alarm will not be triggered by moving around the swing circle, although it is occasionally useful to deliberately set an anchor alarm that will alert you to a change in wind direction.

The guard zone should be the length of the rode, plus the distance between the GPS antenna and the bow, plus a small distance to allow for errors in the GPS or anchor position.

A correctly set alarm will only be triggered if the anchor moves. If my anchor ever moves I want to be woken up.

All of which I found was pretty accurate with a car diy system that would alarm and send a txt msg to my phone if the unit moved out of the guard zone.
Ok if already fitted to nav equipment, but it seems the app's are not reliable.

 

[noelex]

Ok if already fitted to nav equipment, but it seems the app's are not reliable.

I generally use my Vesper as an anchor alarm, but when I have tried the various anchor apps they have all worked well.

The only slight drawback of the apps is the GPS signal of phone/tablet below decks, while adequate, is less good than a system with a clear view of the sky and little multi-path distortion. This is especially true in the sleeping area. This slight reduction in accuracy does not have any impact on normal navigation, but ideally for an anchor alarm the position needs to be as accurate as possible. Even a few meters of extra error means a wider guard zone is required.


In many cases an anchor alarm with a wide alarm radius is fine, but occasionally a tight alarm radius is needed. For these situations a good GPS signal is needed to prevent any false alarms.


There are solutions such as using a Bluetooth GPS or WiFi signal from navigation instruments and linking this to your phone/tablet.

 

[petibonvm]

I used Anchor Lite last season. With good success.

There's a problem with Android turning GPS access off when an app is in the background, which the author warns about. If I recall correctly, shouldn't be a problem if you set 'never to to sleep while charging' on the phone, and plug in to a power supply.

I think the pro version allows two paired phones (one on the boat, one with you) to give a remote function. I haven't used the latest version, which should be an update after Google wanted more explicit warnings about apps which track location (which this obviously does).

one thing to take into account: the remote alarm on a second phone is not 100% reliable. the application goes through a third-party server to bypass Google's blocking. I happened to notice that the server had not transmitted the alarm. This issue has been confirmed by the app designer. very good app nonetheless

 

[oldbloke]

Anchor Pro is really useful when chartering. Strange boat, strange places, strange gear plus I am 2 miles away in a taverna or beach bar.