Best anchor drag alarm

[arsenelupiga]

Originally Posted by SkipMark

iOS App called Anchor. It works fine, but it seems to me that the battery-free solution with the pot on the galley bench wins the prize! :-)

I use android Anchor. Always disable it after anchor or mooring place left to purposely trigger alarm and ensure still actually works. So far 100% success rate.

[epiic]

I've tried them all.

Anchor! is the best.

[Don C L]

Originally Posted by SV DESIRE

we use the anchor alert that is on our Watchmate ais system. the system is simple to activate and very accurate. when the boat drifts out of the set parameters it activates a visual and audible alarm.the system also provides a plot where the boat swung. highly recommended.

Welcome aboard here Desire!

[mikedefieslife]

Doesn't just about every chartplotter on the market have an anchor alarm? What's more they can be hooked up to provide alarms over NMEA too to much more powerful speakers.

[SecondBase]

Originally Posted by captmikem

I have used one for years that always works. A 3 lb fishing weight tied with a length of string, dropped just after I drop the anchor, let it pay out as you set your anchor, give it another 10 feet or so, take it below and tie it to a light cook pot setting on a counter or a cockpit seat. it allows you to swing fine, but if you drag it pulls the pot off and it crashes to the sole.



if you are in an area where you do not want to swing, drop it off the stern.



Simple and works without a battery.



M

Sir you have succeeded. Small parts list. Limited, failure-free moving parts. No electricity. Low cost of ownership.

[SecondBase]

Originally Posted by Suijin

I noticed about 6 months ago that all of the anchor alarm apps (that I have..3 or 4) for iPhone had not been updated in quite a while and was getting a similar message about potentially not working with the current OS. I'm wondering if Apple changed some aspect of their API that made it no longer cost effective for them to maintain. It seems like all of those apps are not being maintained.

This is the hidden risk of iOS upgrades. It breaks out into two parts: comparability-technical fails and app builders bricking or paywallling certain features that used to be included.

Never upgrade unless you have a compelling reason.

Never upgrade in the month prior to a cruise.

Understand that if you do upgrade you are rolling the dice on what will no longer work. That is the unstated trade-off of the loudly stated security patches or other upgrade actual benefits.

[conachair]

Originally Posted by mikedefieslife

Doesn't just about every chartplotter on the market have an anchor alarm? What's more they can be hooked up to provide alarms over NMEA too to much more powerful speakers.

That's a lot of amp hours every day compared to a smart phone...

Though I use Opencpn on a Raspberry Pi, pulls about 0.3A, it has a built in anchor alarm.

[noelex 77]

Originally Posted by mikedefieslife

Doesn't just about every chartplotter on the market have an anchor alarm? What's more they can be hooked up to provide alarms over NMEA too to much more powerful speakers.

The problem with chartplotters is on many units the anchor alarm can only be centred on the boat's cuurrent position. An alarm centred like this is not ideal.

The apps on a tablet/smartphone are much better. iDrifter XL is quite good, but there are some problems with this type of system. The GPS signal loses some accuracy without an external antennae and there is a risk of software conflicts and other issues disabling the application in the middle of the night. The anchor alarm is only a secondary device (good anchoring gear is more important) so these issues do not mean these devices should not be used, but there are better systems, and if you anchor a lot these are worth considering.

There are some marine units such as the Furuno GP-32 with a good anchor alarm and also low power consumption. The Vesper AIS units also have what appears to be an excellent anchor alarm. Open CPN also has a great anchor alarm (thanks to those people that have developed this app, it is appreciated) and if installed on a robust and low power computer system can be a great solution.

[atoll]

i have always found that my hard dinghy banging into the stern or aft quarter wakes me up if the boat drags.

also when dropping and setting the anchor i make a mental note of a couple of transits lined up with prominent land marks ,which serves as a very quick way of checking your position should the wind pick up.

old school,no batteries required..............

[mikedefieslife]

Originally Posted by conachair

That's a lot of amp hours every day compared to a smart phone...

Though I use Opencpn on a Raspberry Pi, pulls about 0.3A, it has a built in anchor alarm.

Yes a lot more than 0.3a but not an unreasonable amount. Personally, I leave mine on for at least 24 hours at anchor. I also use Anchor on a spare android phone as a back up.

Originally Posted by noelex 77

The problem with chartplotters is on many units the anchor alarm can only be centred on the boat's cuurrent position. An alarm centred like this is not ideal.

The apps on a tablet/smartphone are much better. iDrifter XL is quite good, but there are some problems with this type of system. The GPS signal loses some accuracy without an external antennae and there is a risk of software conflicts and other issues disabling the application in the middle of the night. The anchor alarm is only a secondary device (good anchoring gear is more important) so these issues do not mean these devices should not be used, but there are better systems, and if you anchor a lot these are worth considering.

There are some marine units such as the Furuno GP-32 with a good anchor alarm and also low power consumption. The Vesper AIS units also have what appears to be an excellent anchor alarm. Open CPN also has a great anchor alarm (thanks to those people that have developed this app, it is appreciated) and if installed on a robust and low power computer system can be a great solution.

If you are singlehanded like me, it is more of a problem to get the charplotter anchor alarm/position directly over where you have anchored, but a general ball park is ok. If you aren't singlehanded then it's simple.

A chartplotter will have a 10Hz gps sample rate compared to just 1Hz in smartphones and tablets. Probably doesn't matter too much for the purposes of anchoring though, but it is another consideration.

Like I said above, I use both.

[conachair]

Originally Posted by noelex 77

Open CPN also has a great anchor alarm (thanks to those people that have developed this app, it is appreciated) and if installed on a robust and low power computer system can be a great solution.

Handy to know wht the boat's been up to as well

[Captain Parry]

Tie it to a piece of your body for a sure fire alarm.

[noelex 77]

Originally Posted by mikedefieslife

If you aren't singlehanded then it's simple.

For an anchor alarm with the fewest false positives you need to centre the GPS location over the anchor.

This is possible with all GPS systems, but to achieve this on some units can be a nuisance. You need to drive the boat forward of the spot you want to drop the anchor hit the anchor alarm and then reverse estimating when you have traveled the distance between your bow and the GPS antennae less the distance the anchor will take to set and then drop the anchor and continue with your normal anchor setting procedure.

You don't always need to worry about these steps. If the wind direction is going to remain reasonably constant and especially if you are in an anchorage where it possible to drag a reasonable distance before there is going to be a problem, then a less precise anchor alarm is fine.

However, it is easy to end up with an alarm that produces false alerts, or is insensitive and does not provide any useful warning, or both of these problems!

There are some other practical problems. If the chart plotter is turned off even briefly the drop point is lost. The sensitivity can only be set in 0.01 nm steps (about 19m) which is a little coarser than is ideal

The better systems alow the anchor alarm to be centred independently of the boat position. This is easier than the above. A precise anchor alarm can be set at any stage. It can also be set to alarm if boat swings, in a particular direction. This can sometimes be useful.

Hopefully in the near future chart plotter manufacturers will copy the apps and start to fit better anchor alarms.

[Wanderlust]

I use Anchor Alert on Android.

When testing the anchor set with the engine in reverse, enter the rode length (or more accurately, the distance from helm to anchor), point the phone to the anchor and press SET. The inbuilt compass and GPS calculate the anchor position.

The downside is battery drain overnght so it's a good idea to keep the phone plugged in. Also, some phones have better GPS signal reception than others.

As for pots and pans systems with heavy weights tossed overboard, it sounds like a recipe for sleepless nights if there is any reversing current flow. Untangling from the rode would be a nuisance.

[rwidman]

Originally Posted by tedowens

........ I do have an alarm on my chart plotter, but it is in the cockpit and too far away to hear. ...........

I suspect your chart plotter has a provision for an external alarm so you could do what I did and connect an external alarm and mount it where I can hear it while sleeping.