Anchor alarm using a Garmin GPS

Thinking of getting a small Garmin GPS to use solely as an anchor alarm, possibly the 152 h or one of the 400 series. This will be mounted below decks next to my berth

The anchor alarm on the Garmin units appears to be based on a movement of the boat from the spot where the anchor alarm is turned on, say any movement of greater than 100 feet. This is different from the anchor alarm on my Nobeltec based computer and Furuno radar unit where I can draw a box and if the boat crosses the line the alarm goes off. I am installing the Garmin solely to save power.

Question for anyone with experience, if I am setting the Garmin anchor alarm after I have anchored will the normal swing at anchor be a problem?

Is the audio alarm on the Garmin units loud enough assuming we are light sleepers?

Because we are in the Eastern Caribbean the cell phone based alarms are not feasible. Also because the unit will be way below deck I will want to use an external antenna, with nightly use I am also planning on a wired power source.

Thanks

I use a Garmin (192C) on my bridge helm and set the anchor alarm quite often.
Normal swinging (aka anchor dance) will not set it off, but at 100 feet it will when the wind shifts or possibly if the wind dies and the rode goes slack.
I normally have out about 100 feet of chain and I have to use around 200 feet on the alarm for it to not give false alarms.
I really should put in a buzzer to the aft berth, as the volume is pretty low. I can barely hear it when I sleep lightly, but you never know.

The anchor alarm sounds if the boat moves more than X number of feet (whatever you set it at) from the location of the boat when you turn the alarm feature on. If you set it at 100', that would be a circle with a 100' radius from the point where you set it.

If you already have a GPS system with this feature, why not just wire in an external alarm and place it where you can hear it?

I have a dedicated alarm and like it a lot.

Boathooked.com: Anchor Alarm

My boat drags the anchor often in the grassy bottom and windy conditions where we boat. I set the alarm on a fixed Garmin at helm and I can hear it in the cabin ... but my boat is small and I sleep with one eye open. It works exactly like rwidman described it above.



I also experimented with AnchorAlert app for iPhone/iPad. It works more like your Nobeltec where you set a perimeter. There are other similar apps out there. You do not need cell coverage for this to work (after you load the map of that area), just decent GPS signal in your cabin, or wherever your iPhone/iPad is located.

With our stateroom three floors below we use a wireless baby monitor with the receiver on the night stand by my pillow. Inexpensive and it works.

LUVN LIFE said:

With our stateroom three floors below we use a wireless baby monitor with the receiver on the night stand by my pillow. Inexpensive and it works.

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Yes that would work and save the effort of pulling wires through the boat.

rwidman said:

Yes that would work and save the effort of pulling wires through the boat.

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Where's the fun in THAT? :lol:

You stated you were looking for this setup to save power, so can I assume you'll be using the batteries in the GPS? If so you may want to see how long they will run the GPS. I have the Garmin 192 (?) and I doubt the 2 AA batteries would last through the night unless they were new that evening.

To clarify my concern about power usage, my current navigation desktop computer uses 11 amps of DC power through the inverter with the monitor off. A small Garmin GPS with anchor alarm uses less than one half of an amp. I would not be using the batteries in the GPS.

Bay Pelican said:

To clarify my concern about power usage, my current navigation desktop computer uses 11 amps of DC power through the inverter with the monitor off. ........

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That sounds like a space heater with a keyboard.

Have you considered switching to a laptop?

https://play.google.com/store/apps/details?id=air.DragQueen

Why buy, when you can use your phone! I have this on my phone and it works great. Place it on the night stand next to your bed.

rwidman said:

That sounds like a space heater with a keyboard.

Have you considered switching to a laptop?

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Desktop units are power hogs, between 75 and 250 watts depending on the unit. However, they are cheap, mine was $250, and for navigation underway the power use is not an issue. At anchor power is key. A dedicated laptop is my alternative to a small Garmin, as I could use my now obsolete netbook which uses 18 watts (110 volts). The netbook will not power an external monitor so I avoid using it for navigation.

Strangely the costs are about the same to use an existing netbook as buying a small Garmin. My navigation software is Nobeltec and they will charge $150 (USD) for a second dongle and require an upgrade on all navigation area software at $150 an area.

Garmin handheld GPS - get the 12v cigarette adapter

Our chart plotter at the helm uses too much energy and we can't hear the alarm in the aft cabin, so we use the Garmin 76c with the anchor alarm feature. Installed a 12v outlet by the bed and purchased the 12v cigarette cable for the Garmin (no more AA batteries).

We consider several factors when we set the distance... 1) expected weather, 2) distance to others in the anchorage, 3)distance to trouble (shallows, rocks, channel markers, etc.), 4)how much chain we have out, 5) changing currents/tides, etc. If we expect strong winds or currents pushing us toward trouble, we set a short distance. Otherwise, maybe twice the length of chain we have out plus the distance from the bow to our aft cabin. We sleep like babies.

We also use the Garmin at the helm when underway as a back-up to the main chart plotter. Having redundant GPS and charts with similar but not always the same info is useful.

I have tried Drag Queen a couple of times this season on my I phone and it works pretty well. I can easily hear the alarm from the aft cabin.

jleonard said:

I have tried Drag Queen a couple of times this season on my I phone and it works pretty well. I can easily hear the alarm from the aft cabin.

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Gosh, I learn more good things on this forum. Never, ever dreamed that there was such an app! (Although I gotta say that googling "drag queen" also brings up a few more things that are not anywhere near as interesting).

Bay Pelican said:

Because we are in the Eastern Caribbean the cell phone based alarms are not feasible. Also because the unit will be way below deck I will want to use an external antenna, with nightly use I am also planning on a wired power source.

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I think the smartphone/tablet apps only need GPS input, not a cellular signal.

Set the app while you're at the bow directly over the anchor, then you can work out how big a circle you want around that point before the alarm goes off.

-Chris

There are several APPs for I phone and android both free and paid. Amongst the free ones, AnchorWatch and Anchor Alarm are the best ones around and with better reviews

Portuguese said:

There are several APPs for I phone and android both free and paid. Amongst the free ones, AnchorWatch and Anchor Alarm are the best ones around and with better reviews

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It's hard to know exactly which apps you mean. For iOS, neither AnchorWatch nor AnchorAlarm are free. Free apps have the disadvantage of allowing anyone to write a review without any barrier. It causes lower review ratings. It's a well known problem.

Not that it matters because it's completely free, but I'm the author of DragQueen for iOS and Android.

Another vote for DragQueen!

Xsbank said:

Another vote for DragQueen!

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While moving the 47' to the Detroit river I used DragQueen on my iPad in the berth and it worked fine as did the anchor.