agurney
Active member
Change the range of the alarm. My Garmin has a default alarm at 0.01 NM (around 20 metres), which usually gives a couple of false alarms irrespective of wind/tide. Changing it to 0.02 NM gives a peaceful night.
Alisdair
Anchor watch - electronic or sit on deck?
- Thread starter pagoda
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Change the range of the alarm. My Garmin has a default alarm at 0.01 NM (around 20 metres), which usually gives a couple of false alarms irrespective of wind/tide. Changing it to 0.02 NM gives a peaceful night.
Alisdair
supra30
Member
Horses for courses
I think a GPS based alarm will cover most situations, but it needs to be a flexibile setup to cope with all of the possible scenarios.
Last weekend we anchored on a quiet night in a well known solent anchorage with reasonable holding and good shelter, but a lot of relatively nearby boats lying to either their own anchors or to laid moorings. The nearest boats were a little too close for real overnight comfort, even with settled weather... an unusual swing could have made things a bit tight.
Consequently I marked the anchor position, and also set a 3/4 scope alarm centered on a position between the boat and the anchor. This obviously went off whenever we had a major swing. This allowed me to get up and eyeball the situation each time we swung, confirm distances to everyone else, and reset the alarm based on the new position.
After four or five swings in the first half of the night (based on a combination of current leaving/entering the anchorage in two ways at different points in the tide, and the onset of the land breeze) I had still not seen any movement on our anchor and none of our neighbours had ever been close enough to be of concern. So I reverted to a more liberal watch centered on the anchor itself and enjoyed the rest of my night's sleep.
Regards
Mike
I think a GPS based alarm will cover most situations, but it needs to be a flexibile setup to cope with all of the possible scenarios.
Last weekend we anchored on a quiet night in a well known solent anchorage with reasonable holding and good shelter, but a lot of relatively nearby boats lying to either their own anchors or to laid moorings. The nearest boats were a little too close for real overnight comfort, even with settled weather... an unusual swing could have made things a bit tight.
Consequently I marked the anchor position, and also set a 3/4 scope alarm centered on a position between the boat and the anchor. This obviously went off whenever we had a major swing. This allowed me to get up and eyeball the situation each time we swung, confirm distances to everyone else, and reset the alarm based on the new position.
After four or five swings in the first half of the night (based on a combination of current leaving/entering the anchorage in two ways at different points in the tide, and the onset of the land breeze) I had still not seen any movement on our anchor and none of our neighbours had ever been close enough to be of concern. So I reverted to a more liberal watch centered on the anchor itself and enjoyed the rest of my night's sleep.
Regards
Mike
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Clyde_Wanderer
New member
I have used my Bruce to anchor while away this summer and can say it held quite well.
It was well tested in Sanda bay when we had a westerly F5-6 with gusts to F7-8, I did have a kedge out but it wasent called on.
Admittedly I would not have used the Bruce in Craig house having seen the kelp beds, bet they were full of Pollack.
It is advisable to disable plotter track recording if using anchor alarm or all the memory could be used up very quickly, see pic.
This resulted in me not having any track record from the MOK until I got to Sanda on our return passage, when I realised what had caused the memory to be all used up, as I zoomed in on the the track recorded while on the outward passage.
C_W
It was well tested in Sanda bay when we had a westerly F5-6 with gusts to F7-8, I did have a kedge out but it wasent called on.
Admittedly I would not have used the Bruce in Craig house having seen the kelp beds, bet they were full of Pollack.
It is advisable to disable plotter track recording if using anchor alarm or all the memory could be used up very quickly, see pic.
This resulted in me not having any track record from the MOK until I got to Sanda on our return passage, when I realised what had caused the memory to be all used up, as I zoomed in on the the track recorded while on the outward passage.
C_W
Robin
Well-known member
So in a Solent anchorage with reasonable holding and settled weather by using an electronic alarm you had a pretty unsettled night!
Confidence in your gear and your method of anchoring is the real key IMO or anchoring becomes a nail biting stressful experience. Not being scornful here and a general comment rather than to anyone specifically, just trying to point out that the change from day into night, light into darkness is not a reason for an anchor to drag, unless of course it was never set properly in the first instance. Setting an array of alarms is like merely treating the symptoms whilst ignoring the disease.
By all means have an occasional look see if you wake up for a pee or a drink or whatever but otherwise trust your gear and your technique and a sixth sense will soon develop that will be more reliable.
Ubergeekian
Active member
Last time I anchored I found that the bang of the chain breaking and the gentle thump as we hit the shore about thirty seconds later made a very effective alarm.
prv
Well-known member
The first time, and the one I was thinking of, was Prince William in Norway. I may well have done it since on William or Stavros but it made less of an impression. (I sail roughly once a year on the TSYT ships as WL or DH)
Pete
Robin
Well-known member
I did say trust your gear which implied it was in good nick and of suitable size!
Ubergeekian
Active member
The new chain arrives tomorrow. Anyone want about 10m of rather dodgy 7mm chain?
Black Sheep
Well-known member
I beg to differ.
The plotter track record is extremely useful when up in the night to check the anchor (either because of an alarm, or at the swing of the tide, or just checking). It quickly tells you whether there's a consistent movement, or whether you're just swinging within your radius.
But I've never found a use for a plotter track of where I've sailed.
DaveS
Well-known member
It is advisable to disable plotter track recording if using anchor alarm or all the memory could be used up very quickly, see pic.
This resulted in me not having any track record from the MOK until I got to Sanda on our return passage, when I realised what had caused the memory to be all used up, as I zoomed in on the the track recorded while on the outward passage.
C_W
From memory (the plotter's on the boat) I have a choice of setting the "crumb trail" to record a point either at specified time intervals or when a specified distance has been travelled. I use the latter with a distance greater than a normal swinging circle (but I can't remember the exact setting). This doesn't use up track memory while anchored and leaves a trail typically several days long. To check for movement at anchor I put the cross hairs on the initial anchored position then in the middle of the night a glance shows any difference between that and the "boat" position.
andymcp
New member
I think next time I'm at the boat I should really check and see whether my plotter has an anchor alarm...another useful feature I should probably have discovered by now.... 
Cruiser2B
Active member
Excellent advice. Not sure about all GPSs, but for some you can go into the set-up pages and input the distance between your anchor fairlead and the GPS antenna. This way when you punch the anchor waypoint button it will put the plot at your bow.
DaveS
Well-known member
I've been Lakesailored!
From my post yesterday: "the ideal time to set the anchor alarm is just as the anchor is lowered, so that the guard radius can be set to just greater than scope + boat length, rather than twice that to allow for 180 deg shift."
From my post yesterday: "the ideal time to set the anchor alarm is just as the anchor is lowered, so that the guard radius can be set to just greater than scope + boat length, rather than twice that to allow for 180 deg shift."
noelex
Well-known member
If your primary GPS is not WAAS / EGNOS enabled it is probably at least 5 and more likely 10 years old.
At this age they start to become unreliable, many from an internal battery failure.
IMHO a more modern GPS is probably a wise investment.
The only warning is some sets advertised a SDGPS enabled do not seem capable of picking up the differential signal !!.
noelex
Well-known member
I agree good anchoring gear is the first and most important step, but I cannot understand people that have so much faith in the equipment that they do employ such a simple step as GPS anchor alarm.
Some common examples of an anchor that seem set but subsequently lets go are:
1. Anchor hooked on a rock
2. Anchor fouled lifted and redropped by another boat
3. Another boat drags and catches your anchor
4. Anchor buoy is caught and drags anchor
I have seen all of the above occur.
Many boats carry redundant safety equipment like life rafts an EPIRBS. We do not think our boat will sink be carry this equipment because it provides a back up. Think of an anchor alarm in the same way. Properly set you will get very few false alarms.
Robin
Well-known member
I've seen lots of people fail and drag too but strangely we have avoided doing it ourselves by using good gear and technique to ensure the anchor is properly set from the get go. We have been anchoring out in all weathers for some 40 years now and never had the electronics back then when we learned how to do it. We had 3 GPS/plotters (4 counting a Yeoman), radar and echosounder on our last 2 boats, all of which except the Yeoman had anchor alarm capability, but as we had not dragged in the last 23 years and about 35,000 miles of cruising in just those two boats we never felt the need to use them. In fact the last time I recall dragging was over 25 years back in another boat when with wind over tide the warp wrapped round the keel and frayed through on it's trailing edge. Needless to say the possibility of a repeat was immediately removed by switching to all chain rode which is what we had been used to on our several earlier boats.
It may be very simple to set an electronic alarm, but bearing in mind we come from a long history of successful rather than failed anchorings never saw a need to risk being woken periodically by unnecessary false alarms!
As I said earlier, having arrived and probably spent many daylight hours firmly attached to the sea bed, the transition to overnight and sleep mode will not change that security, except in the mind perhaps, unless some significant change occurs to wind strength or direction in which case a re-appraisal and perhaps some more chain out might be justified before a return to slumberland. We anchor 'defensively' too which means trying to avoid situations where other boats could cause trouble. We very rarely use a tripping line and buoy too because IMO they cause more problems than they solve.
I guess we are just old fashioned!
noelex
Well-known member
I have a 55 kg (121 lb) Rocna on my 47 foot boat. I have owned yachts almost continually for the last 25 years, the last 3 of which I have been full time cruising anchoring for more than 300 days a year. So I hope my anchoring technique is better than most.
Despite this over specified anchoring gear I do not share your belief in the infallibility of the anchoring system.
Most cruising yachtsman have got a story about dragging anchor.
If they don’t, they will.
Robin
Well-known member
So bearing in mind your 55kg Rocna and obvious ability to properly set your gear, how many times have you actually dragged when an anchor alarm would have been of help? Genuine question, not just being argumentative.
The point I was making in an earlier reply (actually to someone else) was that in settled weather in the Solent he had been woken by a false alarm or maybe more than one, in conditions when a genuine problem would be most unlikely.
ColdFusion
New member
Most unlikely, but not certain. If you have the facility for an anchor alarm then why not use it as another tool to stack the odds in your favour?
I would rather be woken occasionally for a false alarm than not be woken in the event of a real alarm.
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Robin
Well-known member
Or alternatively after many false alarms then ignoring the real one because every other one beforehand was crying wolf?
In practical terms on our last boat the instruments with alarm facilities were all way back at the chart table and our cabin was up front. So on being awakened by an alarm and having a quick look and listen and realising it is of no concern, I now have to get up and go silence the thing. No sooner am I back in the land of nod and off it goes again!
In our case we have many years of successful anchoring and have faith in our procedures. We have developed a sixth sense too that wakes us if something isn't quite right, like perhaps a change in the natural cycle of motion or a different noise or similar. I see no reason to try and automate that sixth sense, but if I was a regular drag queen maybe it would be different!
There is also the question of power used, even though we were not short of capacity or ability to charge at anchor (big solar panels and wind genny), because even a small GPS/Plotter will use about 0.5A. That may be relatively small but is still 12Ah per day and we often anchor for long periods.
Maybe this is an age thing. I like electronics but despite having them still don't like to be ruled by them. I still have a mobilephone for making phone calls and a separate camera for taking pictures and wouldn't use an 'app' even if I had one.
Each to their own and I'm not trying to influence others, merely to put the other view.