Best Anchor Watch/Alert/Alarms apps?

[happyendings]

Has anybody experimented with a DIY GRM SIM-based alarm system? There are home units available for a couple of hundred bucks. All of the proprietary turn-key systems require monitoring (yet another monthly bill) and are expensive to boot.

[Training Wheels]

Anybody having trouble with there Vesper anchor alarm? Just did the updates on my unit, and now my anchor alarm keeps showing “no GPS signal”, while everything else is working fine.

[happyendings]

I meant to type GSM SIM-based alarm systems.

[CookiesnTequila]

Originally Posted by ranger42c

Hmmm... Interesting; I'm not really interested in OCPN, but I'll have to think more about TZ.

I can hit MOB on the real plotter as the anchor drops. That's about 30' from the anchor, but at least a semi-known distance. That plotter is NAVNet 3D, essentially the same as TZ, and has a great built-in anchor alarm... but the alarm sound isn't loud enough to penetrate to sleeping quarters. (I could fix that, with wires or a baby monitor or something). OTOH, it also uses too much power to leave on all the time, unless the genset is running (and we don't like to do that overnight).

But I can transfer the MOB coordinates to TZ on the laptop inside the house. Then maybe there's a way to couple that with the anchor alarm function. I haven't found that capability, yet...

The basic TZ anchor alarm on the laptop version seems to only by a circular fence, with the center being at the location of the laptop when the anchor alarm function is initiated. Haven't found a way to edit the anchor "location."

(The other two nav apps we use for general purposes are similar; it's just a circular fence, of radius X or diameter Y.)

I'm also grappling with the idea of correction for where the anchor really sets. I can mark where the anchor dropped, but that's not necessarily -- almost certainly seldom -- the final location where the anchor is really stuck in. I can be pretty exact with rode distance to the anchor, but it starts getting more inexact given not knowing where the anchor is with real precision. I could set the anchor, then drive back up the rode and take a more current location reading... but around here that'd probably add significant time to the process unless I wanted mud all over our foredeck...

In the grand scheme of things, I'm only just trying to improve the accuracy of our process... so it's not like something is really broken.

-Chris

Seriously - have a look at Open CPN! I only use it for anchor watch. It is really easy and good!!! I have use TZ for navigstion but find it totally useless compared to OCPN for anchor alarm.

A circle is exactly what you want once you know exactly where your anchor is.

In OCPN you can tweak where that is constantly. For instance, if the wind shifts and our anchor moves a bit before it resets, we'll get an alarm when we cross the zone, but then if it restets itself, like it almost always does, you can just drag your center/circle over the new center, which is real easy to see because the track on OCPN is showing you where the outside perimeter is.

And you can set two circle zones. One that alarms when you exit and one that alarms if you enter it. It is the only anchor alarm app that I have not found myself saying "I wish it did...."

If power is an issue, get a notebook pc with a gps input and add an extrrnal (cheap) usb speaker.

TZ could learn from OCPN - and it's free!

[CookiesnTequila]

Originally Posted by jmschmidt

A sailor that nervous needs to stay on land.

A sailor that is not that nervous will end up on land!!!

We spend 200+ days on anchor per year, soon to be 365!

[CookiesnTequila]

Originally Posted by noelex 77

In hard or medium substrates a good, rapidly setting anchor will set almost immediately. Less than a metre is common.

In softer substrates the distance will be longer, but it has to be very soft before the distance is enormously high.

However, it is important to allow for the displacement between the GPS antenna and the bow where the anchor is dropped. As the GPS antenna is frequently near the stern, this can be a considerable distance. In our case it is about 14m.

The trace of the track as you drop the anchor is generally very accurate and this is a good method of determining the drop point, but you need to allow for the distance between the GPS antenna and the bow.

Hey Noelex, are you still in the Med, anchoring out all winter?

I use the gps from our class A AIS as the primary position feed to our plotter and nav pc (because I leave the AIS on 24/7, and the AIS allows me to set the position of the GPS antenna relative to where it is positioned on our boat, so I am seriously considering alighning my gps to the bow roller so that when I hit the MOB as the anchor hits the bottom the MOB/anchor coordinates are in the right place.

And you are absolutely right, our Mantus rarely takes its own length to set. And most of the time it doesn't pull out of the ground in a wind shift ( even 180 degrees) - it just rotates while staying dug in. But not always!!!

[ranger58sb]

Originally Posted by CookiesnTequila

Seriously - have a look at Open CPN! I only use it for anchor watch. It is really easy and good!!! I have use TZ for navigstion but find it totally useless compared to OCPN for anchor alarm.

A circle is exactly what you want once you know exactly where your anchor is.

In OCPN you can tweak where that is constantly. For instance, if the wind shifts and our anchor moves a bit before it resets, we'll get an alarm when we cross the zone, but then if it restets itself, like it almost always does, you can just drag your center/circle over the new center, which is real easy to see because the track on OCPN is showing you where the outside perimeter is.

If power is an issue, get a notebook pc with a gps input and add an extrrnal (cheap) usb speaker.

TZ could learn from OCPN - and it's free!

I've been resisting OpenCPN mostly because I see all the many threads in the support forum... I'm just not interested in tweaking software (or whatever else it takes to get it to work) anymore. 40 years ago, I had the patience to do that. These days, if an application doesn't work when I turn it on, I'm not fooling with it. (That's not a critique of OCPN; more like a critique of myself.)

But what you describe sounds useful. Our laptop (no power issues) TZ is about 10 years old, a whole major version (at least) older than current... so I dunno if the current product has incorporated improvements in the anchor alarm function or not. I can only say that ours gives us a circle (good) but not a way to positively locate that circle around the anchor.

-Chris

[CookiesnTequila]

Originally Posted by ranger42c

I've been resisting OpenCPN mostly because I see all the many threads in the support forum... I'm just not interested in tweaking software (or whatever else it takes to get it to work) anymore. 40 years ago, I had the patience to do that. These days, if an application doesn't work when I turn it on, I'm not fooling with it. (That's not a critique of OCPN; more like a critique of myself.)

But what you describe sounds useful. Our laptop (no power issues) TZ is about 10 years old, a whole major version (at least) older than current... so I dunno if the current product has incorporated improvements in the anchor alarm function or not. I can only say that ours gives us a circle (good) but not a way to positively locate that circle around the anchor.

-Chris

Hey Chris
I wouldn't pay any attention to those forums. They are mostly geeks enthusiasts continuoisly improving it, or beginers learning how to use it.

I have the most recent version of TZ, both on a pc and my 1-year old Furuno TZ2 plotter - a pretty significant investment for heading around the world!! TZ is and has been my go-to since we bought our boat and moved aboard 4 years and 10,000 miles ago. I decided ro stick with it and upgrade to current version and charts last year when we did an electronics refit, only because I've invested significant time to learn it. I added OCPN primarily as a backup system because a few close friends use it exclusively. I quickly discovered that its anchor watch funcrionality is vastly better than TZs. After using it primarily for anchor watch, I'm starting to discove its other functionality. I really think OCPN is almost as good as TZ in most stuff and better in some. With all that activity improving and working out bugs, I think we'll see OCPN leapfrog over TZ, or any of the others pretty soon, if it isn't already there.

I have no benefit or reason to promote OCPN, it just amazes me how feature rich and powerful an open/free program can be!

[CatNewBee]

I do not like the available charts on OpenCPN, also the user interface is somewhat strange. It is very resource hungry too.

I do have it, but I do not use it / like it.

[noelex 77]

Originally Posted by CookiesnTequila

Hey Noelex, are you still in the Med, anchoring out all winter?

We love time at anchor, and have managed to spend all our time this way since the sea trials were finished on the new boat. We have not even tied up the boat anywhere since leaving the boatbuilders.

I don’t like giving my position on an open forum, but we are no longer in the Med. The anchoring gear is getting a good test, more often than we would really like (see photo) and has been fantastic. The anchor alarm is on 24/7 when not moving between anchorages. Perhaps we are just too nervous .

Originally Posted by CookiesnTequila

I use the gps from our class A AIS as the primary position feed to our plotter and nav pc (because I leave the AIS on 24/7, and the AIS allows me to set the position of the GPS antenna relative to where it is positioned on our boat, so I am seriously considering alighning my gps to the bow roller so that when I hit the MOB as the anchor hits the bottom the MOB/anchor coordinates are in the right place.

The Vesper does this automatically when the anchor alarm is selected. It works very well. The bowroller stays a more constant distance from the anchor than the stern. Swings and yaws have little or no effect on the distance from the anchor to the bowroller so the trace is very consistent, allowing even small movements backwards to be detected. Small movements backwards are a sign the anchor is under stress and are often a precurser to dragging.

However, to do this, both GPS position and heading information is needed. COG alone will not work. So make sure the AIS has heading input if you want to use this feature.

[CaptFigmo]

I've got Anchor Alert. Paid.
Works great. Lots of features.
Sometimes problem getting a good fix.
But that is a phone problem, not an app problem.
Loud alarm.
Saved me a couple of times.

[George DuBose]

I'll stick with my Raymarine anchor alarm. Hasn't failed me yet, but then again, my Manson Supreme has only dragged once in 10 years and that was when it was fouled by a bushel of kelp in Scotland.

[Mike Banks]

Mine used nothing electric--just 7 mm long-line braided polyester cord (love that stuff) wound on to a Mexican Yo-Yo and doubles as a Tuna line when not used as an anchor watch alarm.

On the front of most anchors is a hole or a welded-on loop for attaching a marker buoy and recovery line in case the anchor becomes snagged on a log or piece of coral. 7 mm commercial fishing long line braid is strong enough to recover an anchor--so it serves yet another purpose to keep it handy. Set your recovery line to whatever is the depth of water at high water springs--err on the excess, and throw the buoy overboard--I use a white foam one visible in a spotlight.

At the same time, or motoring up to the first buoy later, toss a small dinghy anchor overboard alongside the main anchor. It does not have to be very heavy--a small Danforth type is fine. Clipped into this line on a dropper loop tied into the line (Prussick knot like loop) is another plastic buoy, this one a different colour. It is easily fastened to the alarm line at the surface--the anchor end is snap-shackled into the anchor hawse loop. One could have a small length of chain--but since the pull on it is not going to be strong, I never needed to use anything other than just 7 mm line and a shackle.

Both lines and the buoys are paid out as the anchor is lowered and set, then the slack in the alarm line still aboard and connected to the second buoy and small anchor, is pulled more or less clear of the bottom and any likelihood of fouling a propeller. Fit small floats if in doubt--or use floating line instead of long-line braid. Another loop tied in this line connects to a piece of a plastic cutting board. This is an insulator placed between athe jaws of a switch made by the jaws of a spring clip and two metal contacts screwed to each side. I use a plastic spring clamp--they are cheap and bought at any hardware.

You get the drift--pardon the pun.

If the big anchor drags--the small one does not and pulls out the plastic label--the contacts close--and whatever loud alarm you have set up is in circuit and makes a hell of a noise.

This is a variation on the old sailing ship method using an unwinding reel which had spring-loading strikers that hit a bell if the anchor dragged.

The idea of the two buoys is a quick flash of a torch will tell you if they have separated further by any appreciable amount, so if you have an anchor watch--you have an extra warning..

If the vessel swings in the night, it should not change anything--but if you are worried about lines fouling the main anchor--instead of long-line use floating polyester. I have never had one foul--even when the boat swung several times and tracked backwards and forwards in the stream, but in any case--I could easily soft-shackle some small floats to the alarm line if that was any concern to keep it on the surface..

The string and dinghy anchor is as accurate as the slack you leave in it --which in my case is less than twenty metres.

Allow for the tide when setting the floats depth. They do not have to be even close to accurate--just so they do not try to lift the anchors at the flood.

[charly]

the FURUNO GPS-32 uses very little power and has a simple, good anchor alarm (besides beeing a GPS and navigation tool).

[SM2K]

We’ve used for years an app called Anchor! We’ve tried other stuff but never better than Anchor! Easy to use, never failed us. I’ll take a look at drag queen.