Anchor Alarm

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Different approach on the same theme: I go forward of where I want to drop the anchor; set the anchor watch; then drift back and drop the anchor just forward of the spot. This eliminates a lot of the error.

I'm waiting for the real anchor drag alarm system. You will attach a transmitter to your anchor. There will be a receiver hanging off your boat (has to be below the keel). The receiver measures the distances and direction to the transmitter. The receiver takes that information and a GPS position to determine an accurate position of the anchor (transmitter). So instead of monitoring a 200' swing radius of the boat, we keep the anchor in a 25' (to allow for GPS error and anchor reset) radius circle. The transmitter and receiver for underwater use have exited for 20 years already. Someone just needs to build the unit and and the top side box.

Ted
 
Funny, I was just thinking the same thing.
 
I have not been happy with the circle provided by most anchor alarm systems. I have instead drawn a boundary outside of which Bay Pelican should not go using the Nobeltec Max Pro software. This allows me to set the boundary as a multi sided figure with each side located where I believe the boat should not go. For example I may not want to move 150 feet forward if there is a wind shift, or 150 feet to one side or the other.

An example, it is common in the Eastern Caribbean to count on a steady wind from the east for days, thus one can anchor 50 feet west of shallow water and not worry too much about swinging into the shallows. However, I set my anchor alarm boundary so that if the wind does shift and the boat goes forward the alarm goes off.
 
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O C Diver said:
I'm waiting for the real anchor drag alarm system. You will attach a transmitter to your anchor.
Click to expand...

I don't think that'll happen any time soon. It's too easy to just track your position and ultimately, that's what you care about. As a trivial example, it's not unheard of for chain/anchor damage to occur with the chain then disengaging from the anchor. The anchor won't move an inch but my boat might be on its way to Portugal.

As an aside, that scenario is a great reason to keep an anchor alarm alive when on a mooring ball.

But even moreso, by being able to share the positions and anchor set of the boats around me, I can not only monitor their anchor dragging but can also plan my anchor drop based on where they are in their swing, how much they've let out, etc. That doesn't require any wizbang electronics or antenna technology. It just requires an internet connection (or perhaps some of the digital uses being petitioned to the FCC for low power, near use data over one of the marine VHF channels). This is also an obvious extension for AIS which, let's face it, will eventually be required for "homeland security" reasons.

Connectivity, communications, and collaboration are where everything in marine electronics is going. Why not anchoring?
 
Bay Pelican said:
I have not been happy with the circle provided by most anchor alarm systems.
Click to expand...

You make an excellent suggestion of environmentally-modified anchor alarm zones based on knowing more about an area or being concerned about specific wind shifts.

One other thing to think about...the subject of an upcoming newsletter sure to generate debate here too!

If you set an anchor alarm and the system draws a nice, perfect circle on your nautical chart, there's an error in what you're seeing. This is more noticeable in Maine where I first came across it.

Nautical charts are nearly always displayed with a Mercator projection. When the software developer throws up a perfect circle on the display, they're doing it too cheaply, probably using a built-in API call to draw the circle with a single function call. To do it right, the circle needs to be manually created because it too should be Mercator-projected - few developers understand the trigonometry and projection math needed to do this. Unless you're getting close to the equator, the circle will always look pretty squashed. And yet, they usually don't...
 
If you use a pad or phone anchor alarm.....

Based on our anchor setting videos and one is reasonably assured your anchors sets and holds quickly, if you mark from the bow, right where the anchor drops and hits bottom, the add the distance from the bow to wherever you put the device for the night.....add scope.....isn't that a pretty good radius for your swing?

Yes add 10 feet for GPS error another say 10 for initial drag or as much you thought it did drag, and another 5 for slop....I would think that would work for most of us that uses a pad or phone for an anchor alarm app.

This isn't my idea....someone else posted this year's ago when anchor alarm apps were getting a lot of discussion.
 
Jeffrey S said:
I don't think that'll happen any time soon. It's too easy to just track your position and ultimately, that's what you care about. As a trivial example, it's not unheard of for chain/anchor damage to occur with the chain then disengaging from the anchor. The anchor won't move an inch but my boat might be on its way to Portugal.
Click to expand...

Pretty simple to add a settable maximum value alarm between transmitter and receiver. Would also know where to find my lost anchor. :rolleyes:

Jeffrey S said:
As an aside, that scenario is a great reason to keep an anchor alarm alive when on a mooring ball.
Click to expand...

Clip the transmitter to the mooring ball or pendant.

Jeffrey S said:
But even moreso, by being able to share the positions and anchor set of the boats around me, I can not only monitor their anchor dragging but can also plan my anchor drop based on where they are in their swing, how much they've let out, etc.
Click to expand...

I don't think anchoring information over the internet is going to gain more than modest acceptance. But anyway, you're not monitoring their anchor dragging; you see their boat move and are only guessing why.

I don't care only where they are, I also want to know where their anchor is and how much rode they have out or if they extend it. Your system doesn't tell me that or if they're laying to the wind, current, or both. They may even be softly aground. If I knew where their anchor was and length or rode, I could position myself better to not be hanging over their anchor when they want to leave in the morning.

Jeffrey S said:
That doesn't require any wizbang electronics or antenna technology. It just requires an internet connection (or perhaps some of the digital uses being petitioned to the FCC for low power, near use data over one of the marine VHF channels). This is also an obvious extension for AIS which, let's face it, will eventually be required for "homeland security" reasons.

Connectivity, communications, and collaboration are where everything in marine electronics is going. Why not anchoring?
Click to expand...

Think the right to privacy laws and the courts will prevent that. They may establishing more controlled area's that require AIS to enter, much like controlled air space around cities, military bases, and airports.

While I think you will see more acceptance of AIS, don't think advertising your anchorage for the night on the internet is going to gain widespread acceptance. While your system is innovative, if the boats around me don't agree to share their information with me over your system, then they don't exist to me on your system, do they?

Ted
 
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference. We have poor ability to judge distances for one thing. And chart plotters only give you a good theory as to where you are. I found the radar handy on a few occasions, even in daylight, and alsways in poor visibility, as it was already on anyway.
 
caltexflanc said:
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference. We have poor ability to judge distances for one thing. And chart plotters only give you a good theory as to where you are. I found the radar handy on a few occasions, even in daylight, and alsways in poor visibility, as it was already on anyway.
Click to expand...

While I haven't tried it, I guess if you had radar with plotter overlay and ARPA, you could mark the boats around you, turn on the tail feature, and track the boats and their position changes as they swing on their anchors.

If I need that, I probably need to find a less crowded anchorage.

Ted
 
caltexflanc said:
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference. We have poor ability to judge distances for one thing. And chart plotters only give you a good theory as to where you are. I found the radar handy on a few occasions, even in daylight, and alsways in poor visibility, as it was already on anyway.
Click to expand...

Never tried it, but interesting idea.
 
O C Diver said:
But anyway, you're not monitoring their anchor dragging; you see their boat move and are only guessing why.
Click to expand...

Well, you'd need to read another newsletter about Community Anchoring to get the full design. But yes, it would be trivial to provide all information about the anchor set like I wrote in my posting a couple above.
 
Jeffrey S said:
Well, you'd need to read another newsletter about Community Anchoring to get the full design. But yes, it would be trivial to provide all information about the anchor set like I wrote in my posting a couple above.
Click to expand...

Ok, but what about this part?

O C Diver said:
While your system is innovative, if the boats around me don't agree to share their information with me over your system, then they don't exist to me on your system, do they?
Click to expand...

Ted
 
Jeffrey S said:
It's just a little odd that we're willing to spend $10K ($40K?) on electronics for our trawler and yet don't expect it to work together to solve basic trigonometry to provide one of the most important alarm systems on a boat. Worse than that, most people don't even know the problem exists or why they need to set an anchor alarm at 200' when they only put out 75' of chain with 5:1 scope. Making that sound like it's the accuracy of a "gnat's a$$" shows a total lack of understanding about the potential issue unless you live in the world of giant friggin' gnats. I mean, the Chesapeake has bugs but my experience there has been volume of bugs, not size.
Click to expand...

Indeed. And of course the difference between 75" and 200' would be way honkin' bigger than a measly ol' gnat! :)


But that last 5-10' of accuracy? Even if easily doable... trivial.



caltexflanc said:
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference.
Click to expand...

Yep, all the time. Not so worried about the other boats -- usually -- but that can be useful sometimes... and distance to shoreline is almost always useful in our circumstances. Usually that means some follow-on calculations (estimations) about distances to charted shallower water in between boat and shoreline, another useful factoid we pay significant attention to.

-Chris
 
caltexflanc said:
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference. We have poor ability to judge distances for one thing. And chart plotters only give you a good theory as to where you are. I found the radar handy on a few occasions, even in daylight, and alsways in poor visibility, as it was already on anyway.
Click to expand...

Several times I have used a combination of radar, digital charts and eyesight to draw a chart of the various boats around me in an anchorage in advance of a sever storm front hitting after dark. If my anchor lets go, or the mooring ball fails in the dark I feel a chart of the other boats may be useful.
 
caltexflanc said:
As a sidelight to this discussion, I wonder how many here turn their radar on to calculate and mark other boats and shoreline or points of reference. We have poor ability to judge distances for one thing. And chart plotters only give you a good theory as to where you are. I found the radar handy on a few occasions, even in daylight, and alsways in poor visibility, as it was already on anyway.
Click to expand...

I do just that a lot.
 
We anchor quite a bit but I have never used an anchor alarm. Headed out for two days on the hook tomorrow, solo, and I won't use an alarm. I get it, a good thing to do. But I feel if I set the hook well, watch it all day and into the evening, things are normally solid. The only time I had issues coming unglued was at the initial drop off when I caught a plastic bag or other things down there and it was apparent the anchor was not holding.
 
O C Diver said:
I'm waiting for the real anchor drag alarm system. You will attach a transmitter to your anchor. There will be a receiver hanging off your boat (has to be below the keel). The receiver measures the distances and direction to the transmitter. The receiver takes that information and a GPS position to determine an accurate position of the anchor (transmitter). So instead of monitoring a 200' swing radius of the boat, we keep the anchor in a 25' (to allow for GPS error and anchor reset) radius circle. The transmitter and receiver for underwater use have exited for 20 years already. Someone just needs to build the unit and and the top side box.

Ted
Click to expand...

Something similar actually exists, but the approach is a little different. A device is attached to the anchor chain, a few feet up from the shank. Inside the device is an accelerator -- if the chain moves, it knows and sends the equivalent of a sonar signal toward the mother ship. A device on the mothership receives the signal and, based on sensitivity settings, etc., alarms as appropriate.

I had one on my last boat and like it quite a bit. As I recall, the only improvement I wished for was an ability to detect when it lost communication, as might happen if the sending units batteries were drained, or if the signal wasn't directly enough pointed back to the boat (the signal being fairly directional).
 
MYTraveler said:
Something similar actually exists, but the approach is a little different. A device is attached to the anchor chain, a few feet up from the shank. Inside the device is an accelerator -- if the chain moves, it knows and sends the equivalent of a sonar signal toward the mother ship. A device on the mothership receives the signal and, based on sensitivity settings, etc., alarms as appropriate.

I had one on my last boat and like it quite a bit. As I recall, the only improvement I wished for was an ability to detect when it lost communication, as might happen if the sending units batteries were drained, or if the signal wasn't directly enough pointed back to the boat (the signal being fairly directional).
Click to expand...

Sounds interesting, who makes it? Does it alarm on wind or current reversal?

Ted
 
Fascinating discussion and info, I am doing a great audiobook on the settlement of America by the British in the 1600 to 1700's, wonder how they did it:) B
 
fletch said:
Fascinating discussion and info, I am doing a great audiobook on the settlement of America by the British in the 1600 to 1700's, wonder how they did it:) B
Click to expand...

Probably had someone stand watch 24/7.

Ted
 
mbevins said:
Jeffrey ?
Click to expand...

Yeah, there's a reaction like that from some people, I guess, who aren't sure about their sexual orientation so they can't stand to see something called DragQueen on their phone. I guess it makes them ask questions every time they see it...

There have been 80,000 downloads of the app. It gets launched a few thousand times every week so someone is getting some utility from it.

:D:D:D
 
Jeffrey S said:
Yeah, there's a reaction like that from some people, I guess, who aren't sure about their sexual orientation so they can't stand to see something called DragQueen on their phone. I guess it makes them ask questions every time they see it...

There have been 80,000 downloads of the app. It gets launched a few thousand times every week so someone is getting some utility from it.

:D:D:D
Click to expand...

Or we could have young children who use our iPads.

Smart name, but stupid, and not Credo based, at the same time.
 
It`s just a pun,not calling for the revival of the Spanish inquisition.
But should you google it around Mardi Gras time? Maybe not.
I heard the phone should be on charge as the app draws substantial current. (Oops, another pun).
 
BruceK said:
I heard the phone should be on charge as the app draws substantial current. (Oops, another pun).
Click to expand...

I think people who don't like the name are rather sad. It's funny how most people tell us how much they love the name. They're usually the ones out there really anchoring...

To significantly reduce the battery usage, turn the brightness down all the way (it's still too bright in bed at night) and put the phone into airplane mode. At least for iOS, Apple changed airplane mode a couple of versions ago. It now turns off all radios but leaves on the GPS.

With those settings, a fully charged normal iPhone 6 will run all night with DragQu$$n (the name that must be kept hush).
 
My two college age children had a field day harassing me when they saw the app on my phone.?
 
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