wonkywinch
Well-Known Member
The plotter should have an offset option so you can set it to a position if your choice in the same way you can adjust the depth to read water, below keel etc.
Anchoring
- Thread starter magicol
- Start date
Chiara’s slave
Well-Known Member
I’m afraid it all seems rather like shaking it 10 times, wrapping it in your shirt tails and wearing a nappy on top, to me. Life can be simpler, sometimes.
noelex
Well-Known Member
It is a valuable feature in Vesper Vision AIS/anchor alarm (and also open CPN?), but unfortunately very few chartplotters offer this facility. When available it obviously requires heading information (not just COG) so you also need a fluxgate or GPS compass.
The anchor alarms on even expensive chartplotters tend to be very rudimentary.
14K478
Well-Known Member
“Whatever did we do before fancy anchors and chart plotters?”
We noted transits and - something nobody has mentioned yet - we used our ears. The sound the chain makes if an anchor is dragging is different to the sound it makes if the chain is being re-arranged on the bottom.
We noted transits and - something nobody has mentioned yet - we used our ears. The sound the chain makes if an anchor is dragging is different to the sound it makes if the chain is being re-arranged on the bottom.
Chiara’s slave
Well-Known Member
When the norm for us might be half the distance from shore that ypu deep keel people are, you don’t need to use a bearing compass. It’s bloody obvious if you’re dragging. My favoutie kind pf anchorage is to bury the hook myself on the beach.
NormanS
Well-Known Member
On one occasion when we did drag, fortunately away from the land, I became aware that instead of first heeling one way and then the other, as the boat swung to her anchor, she heeled the one way for too long. Sure enough she was dragging. Unconsciously, I was in tune with the boat's behaviour.
GHA
Well-Known Member
You're actually allowed to still do that and have all the modern toys.
Transits will be out when the wind changes direction.
Wouldn't know what a chain dragging sounds like
Roberto
Well-Known Member
Lay it over a flat rock bottom and put the engine in reverseWouldn't know what a chain dragging sounds like
GHA
Well-Known Member
I'll take your word for itLay it over a flat rock bottom and put the engine in reverse
Personally prefer having an alarm go off if the boat moves a metre or 2 further that it should
lustyd
Well-Known Member
No! You must choose! And choose wisely as you only get to pick sides onceYou're actually allowed to still do that and have all the modern toys.
Transits will be out when the wind changes direction.
Wouldn't know what a chain dragging sounds like
oldmanofthehills
Well-Known Member
How does that work with 30m of chain out and you go 60m the other direction when the tide or wind turns? Even in shallow water we move in a 10m circle, and we set alarm for 50m if anchoring further out and unsure. However once the Manson sets for certain we dont bother with alarm, as only relevant when trying to catch the boulders on the fringes of Barn PooleI'll take your word for it
Personally prefer having an alarm go off if the boat moves a metre or 2 further that it should
GHA
Well-Known Member
Just a simple radius. If the boat goes outside whatever radius you set from the anchor then the hook has moved and the alarm goes off.
benjenbav
Well-Known Member
Surely the furthest you will go without dragging is slightly less than 2X metres where:
X = sin@ * h
Where
@ = angle of rode to perpendicular at lowest point of tide
h = length of rode
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noelex
Well-Known Member
&
If an anchor alarm is correctly set it will alert the user when the anchor moves even a small distance, but at the same time it does not give any false alarms if the wind direction changes.
Often before an anchor breaks out and drags it will move slowly backwards. This is a warning that the anchor is approaching its limits of holding.
In practice and with care, the alarm distance can be set to less than 5m to trigger an alarm if the GPS records the anchor has moved more than this amount. In most cases these tight alarm distances are not needed because there is ample drag room before the yacht will sustain damage, but on some occasions this can be useful.
The alarm centre should be set over the anchor position. Therefore swinging around the anchor with a change in wind or current change does not effect the alarm.
If an anchor alarm is correctly set it will alert the user when the anchor moves even a small distance, but at the same time it does not give any false alarms if the wind direction changes.
Often before an anchor breaks out and drags it will move slowly backwards. This is a warning that the anchor is approaching its limits of holding.
In practice and with care, the alarm distance can be set to less than 5m to trigger an alarm if the GPS records the anchor has moved more than this amount. In most cases these tight alarm distances are not needed because there is ample drag room before the yacht will sustain damage, but on some occasions this can be useful.
oldmanofthehills
Well-Known Member
Exactly, which is what I said we did. Not merely a metre or 2 as in your post Mr GHAJust a simple radius. If the boat goes outside whatever radius you set from the anchor then the hook has moved and the alarm goes off.
GHA
Well-Known Member
"if the boat moves a metre or 2 further that it should"
Obviously from the anchor.
It's a web forum here, like talking down the pub. We ain't drafting legal documents.
GHA
Well-Known Member
I usually dig the hook in pretty hard and normally set the alarm a maybe 5m further than the max tracked radius but playing around it can be down to maybe couple of metres without any false alarms even in 25/30Kt gusts. Raspberry Pi does it all with a signalk anchor alarm app & the Pi is also the boat sound system so the anchor alarm & off course/high wind etc in opencpn watchdog are all speech which is really useful! No "what's that beep mean again"
. And she's got a nice calm voice
noelex
Well-Known Member
I admire your level of sophisticationAnd she's got a nice calm voice
. In my case I jump out of bed in a panic, only to discover the batteries in the smoke alarm are flat .Snowgoose-1
Well-Known Member
My lady fire/co alarm warning on the boat is aptly urgent but still rather inviting. Are all alarms female ?And she's got a nice calm voice
GHA
Well-Known Member
Saving this one for something special
https://www.wavsource.com/snds_2020...03/tv/simpsons/homer/run_for_your_lives_x.wav
