Any Comments on My Anchor Alarm?

[barnakiel]

Originally Posted by ActiveCaptain

It just doesn't work that way. Again, if your GPS is on your stern of a 45' boat, your error is 90 feet without your anchor dragging 1 inch.

If you drew it out on graph paper you'd see it. I know it doesn't feel like it could be that far off but it really is.

I do not need the graph to visualise this. I have anchored hundreds of times and used the GPS 'anchor alarm' half of the time perhaps. This is just one of the limitations and I make do with it.

Then there is the depth alarm (upper and lower) and there is the real anchor drag thing (expensive).

So, we have some options, they have their limitations - I have not see any solution to these limitations in this thread.

If we could only use the stake, like my grandpa when he went out fishing ;-))

b.

[Arcen]

While not exactly "Anchor Alarm", this guy is doing something similar as far as microcontroller vs phone (computer in this case) and waking up in the middle of the night: Nomadic Research Labs - Live Page
From my understanding of things, he has a set of microcontrollers that are hooked up to lots of sensors and collect a variety of information on various systems. Then a low powered computer polls the microcontrollers at set intervals for information and stuffs the data into a database. Then a set of php(web) pages displays the information in human readable format for status checks. He also has the ability to set alarm conditions (If sensor is < 5 or > 100 or what have you, do an alarm.) The microcontroller can wake the main computer up and sets the computer to activate the alarm. He seems to love text-to-speech, so he would wake up to a computer voice shouting at him "The water in the bilge is now 18" deep!" or "Anchor has dragged by 15'. Currently heading SE. Wind Speed is 40 knots. Water depth has decreased 10' in the last 5 minutes." Having that information in the foggy moments of waking up would be extremely helpful. A very interesting system, and can't wait to see how it holds up to the rigors of being in a boat.

[nodee]

Originally Posted by Islander

How about this? (It's a bit like "a train leaves Chicago going 80MPH ..) Come to think of it, 306 feet is a long drag, so it would be better to calculate the point directly above the anchor and allow 153 feet of drag from that point.

Islander's math looks pretty good to me.

[ActiveCaptain]

Originally Posted by Paul Elliott

In my NavMonPc...

I like that design - I've never seen it. The only issue it has is that you don't get the "circle" until you've been at anchor for a while. But still, if the anchor drags when it is first put down, there's no swing error and you generally know pretty quickly.

I looked at the site and screen shots:
http://www.sailvalis.com/NavMon/

There's a lot to like about that - some very clever ideas.

Why couldn't that just run on a phone too?

[Hudson Force]

Originally Posted by ActiveCaptain

How well does it work of the current changes during the night and swings you around? That's sort of a common thing when anchored.

This was asked in regards to setting a dinghy anchor at the bow tied to a small line that I lead through a cowl vent tied to a sauce pan on the floor of the head.
The sauce pan never fails to hit the headliner of the cabin when the current turns the boat. Some may consider this a "false alarm", but it's only once during the night and I welcome the opportunity to see how I set, especially in a crowded anchorage, when the current changes. 'take care and joy, Aythya crew

[Therapy]

Originally Posted by Eric M

RC,
Since you asked what others are using...
I use a Garmin 76CSx handheld plugged into a 12V outlet in the forward cabin where we sleep. It draws less power all night than the two reading lights we use for an hour before bed. It draws a track of where we have been so if the alarm does go off I can see clearly where we are compared with where we have been. Keeping it in the forward cabin right next to my head it is <10' from the bow so no worries about the swing arc of the stern vs the bow. Best of all, the alarm goes off when we pull anchor if I have forgotten to turn it off and unplug it keeping our backup GPS physically isolated from the electrical system on the boat.
Hope that helps.
--Eric

My answer is; I just ordered the 12v cable.

[Paul Elliott]

Originally Posted by ActiveCaptain

I like that design - I've never seen it. The only issue it has is that you don't get the "circle" until you've been at anchor for a while. But still, if the anchor drags when it is first put down, there's no swing error and you generally know pretty quickly.

I looked at the site and screen shots:
NavMonPc

There's a lot to like about that - some very clever ideas.

Why couldn't that just run on a phone too?

That's why I mentioned it -- hoping that you (or someone) would do the phone app!

The NavMonPc anchor watch design evolved with the extensive help of some of the users. For the latest version of this (free) program, and a much-improved user's guide, look here: http://www.NavMonPc.com

Another platform that I like is the PocketPC (which is being eclipsed by the iPhone, iTouch, etc). I originally wrote NavMonPc for the PocketPC, which only draws about 0.1A when charging. When the low-power Netbooks started showing up I migrated the program to the Windows PC platform to get the improved user interface, but the extremely low-power PocketPC still has a lot to offer. I'm thinking about building a stripped-down version of NavMonPc for the Pocket PC -- a full-circle of sorts!

[motion30]

Originally Posted by ixtlan22

I'm trying to train my dog so that when I'm ashore he reads the chartplotter and barks out a warning if the anchor starts to drag...he's doing good but he's kind of a slow learner...so far he's just up to crapping in the cockpit.

Maybe if he was trained as a seeing eye dog Does he clean up after himself?

[James Joll]

We have the Garmin 76C5x. This must be one of the least user friendly devices made. How to set an anchor alarm ? Also is there an additional cable to power it from the house 12v.
I have found the simple I phone app to work well enough.

[ActiveCaptain]

Originally Posted by Paul Elliott

Another platform that I like is the PocketPC...

I've written 2 full chartplotter products for Pocket PC/Windows Mobile (and other platforms). You'd be surprised how many people still use Windows Mobile.

I have about 2 years of projects ahead of me right now - but I'd eventually like to get around to doing a lot more mobile phone apps for many different boating related things.

[Therapy]

Originally Posted by James Joll

We have the Garmin 76C5x. This must be one of the least user friendly devices made. How to set an anchor alarm ? Also is there an additional cable to power it from the house 12v.
I have found the simple I phone app to work well enough.

You got that right.
The menu system is just plain BAD.

Anyway, it can be done.

http://www8.garmin.com/manuals/GPSMA...nersManual.pdf

Page 46.

Setup menu > marine > anchor alarm.

And I just ordered a power cord.
Somewhere here.

garmin 76csx 12v cable - Google Product Search

[R_C]

Everyone,

Thanks for the discussion. I appreciate the comments, suggestions, and information about what everyone is using or would like in an anchor alarm. From the skillet on a dinghy anchor, to the handlheld GPS and chartplotter there are a number of solutions.

So far, I’ve learned that the only drawback to my device is the possibility of dropping it overboard when using it at the bow while anchoring. Adding more features to show the boat’s current position graphically would be cool but that violates one of my design goals, which is to keep the device simple. Some of the other suggestions might mean relying on external devices (bluetooth, wifi, phone) which could add additional points of failure and add to the cost. One add-on I’ve considered is to send a text message to a phone when the alarm sounds.

If I proceed, I will have to redesign with manufacturing in mind so I’m still not sure what the final cost would be. But would you pay $250 for a standalone, single-purpose, portable anchor alarm?

- Rick

[R_C]

Originally Posted by James Joll

We have the Garmin 76C5x. This must be one of the least user friendly devices made. How to set an anchor alarm ?

I have a Garmin 76C and its anchor drag alarm is not terribly useful. If it would let me see the distance between the anchor mark and my current position that would be a huge improvement. But it does not. I wanted a better mousetrap so I created my own anchor alarm.

- Rick

[nodee]

I'm thinking some type of anchor float with "Spot" or similar GPS bluetooth sender to an iPhone app may be of use here.

[Caribsailors]

As I've progressed through life my hearing and other parts of my body haven't kept up.

I have had to moved to phone & alarm clocks with a vibrate feature which has helped a lot.

Most alarms on the YOT are out of range of my useful hearing even with bionics and having a feature of a selectable tone range and an output that could go to a pillow placed vibrator.

Just a thought.

Cheers