Anchor drag alarm + hints page

Paul S · Post by **Paul S** » Tue Jan 08, 2008 8:23 am

Was browsing and found this interesting article
http://www.yandina.com/anchAlrm.htm

How to make a (non gps/loran/etc) anchor drag alarm. Seemed pretty neat! To me at least!

Also found this page (same site, different page) with tips:
http://www.yandina.com/hints.htm

Post by **Russ** » Tue Jan 08, 2008 9:30 am

Kind of reminds me of my homemade anchor alarm.

I used a hunk of heavy chain about 1 foot in length for the weight. It was what I had and was heavy enough. Anything heavy (lead weight) would work.

Tie the weight (chain in my case) to a lightweight string and toss it as close to the anchor as possible. Pay out the string along the anchor rode into the boat into the forward hatch where I'd attach it to my "box".

My alarm box was basically a pull chain switch like you'd find on a ceiling fan or lamp attached to a loud buzzer.

Parts:
Plastic box
Pull chain switch
Battery box for 2 D cell batteries
Buzzer (3 volt from Radio Shack)

Drill hole in side of box, screw pull switch it.
Wire batteries to switch to buzzer.

Attach string from weight attached to string (on the bottom near my anchor) to pull chain on my alarm box which was inside the cabin.

If the anchor drags, the string becomes taught and pulls the chain switch setting off the buzzer.

Simple simple design and worked quite well.

The design in the link is somewhat improved. If my pull switch got pulled twice, it would shut OFF the alarm. However, the bobbing of the boat would pull the switch again and turn it back on.

The alarm magnetic switch in the link would close the circuit and not open it again until a human reset the device. Kind of like a mouse trap.

MacShales · Post by **MacShales** » Wed Jan 09, 2008 6:30 pm

Paul:

You've got a GPS right??
I just set my Garmin to Anchor drag mode and it's gone off once all last year.
Are you interested in something more sensitive??
When I stumbled on deck after the alarm, I found I had moved a grand total of 15 feet. I just set the sensitivity to a reasonable number.

Wouldn't that be easier??

Take care, Brian

Paul S · Post by **Paul S** » Wed Jan 09, 2008 6:35 pm

THe idea is when you spin around an anchor the diameter can be pretty wide..If you set it to say 50'....50' around a central point is VERY different than 50' from your current location straight back (dragging 50'+).

this mod you can spin around the anchor and it wont go off..but dragging back would (in theory) trip it.

I just found it interesting, thats all

eric3a · Post by **eric3a** » Wed Jan 09, 2008 7:09 pm

MacShales · Post by **MacShales** » Wed Jan 09, 2008 9:48 pm

Ok, that makes sense give you do swing thru 2x the radius of the anchor rode given a 180 deg swing in wind or current. I get ya now.
I think I'll go check out the link.

Regards, Brian

Night Sailor · Post by **Night Sailor** » Thu Jan 10, 2008 9:42 pm

Like Eric, I tend to wake up at any change in boat motion and I always check to see why. Never miss the sleep if I wake up that way.

However there is a simple, low tech solution to making an anchor alarm if needed. One old tin can with lid, a hand full of old nuts and bolts inside. A small line tied to the tin can and to a heavy weight like lead or chain or old wrench. Drop weight straight down from bow after you have firmly set your anchor. Place tin can alarm on the deck or cockpit or dining table with about 10 ft of slack in the line. If the boat swings far enough or drifts enough to pull over the can, the nosise will wake you so you have a chance to see if all is well. Cost is near zero. Effectiveness very good. No skill required to make.

Catigale · Post by **Catigale** » Fri Jan 11, 2008 3:50 am

Ive got a great Anchor Alarm which automatically wakes me and tells me " Honey, we're dragging"

She has many other benefits too numerous to post here.

Ive found the change in motion doesnt wake me up unless its drastic - but one thing that does wake me up is listing....as I found out at 3am taking on water....

Paul S · Post by **Paul S** » Fri Jan 11, 2008 7:24 am

Catigale wrote:Ive got a great Anchor Alarm which automatically wakes me and tells me " Honey, we're dragging"

She has many other benefits too numerous to post here.

Ive found the change in motion doesnt wake me up unless its drastic - but one thing that does wake me up is listing....as I found out at 3am taking on water....

damn u got the anchor alarm... i got the heeling alarm on our boat..at 20-25 the alarm goes off until the condition is corrected!

KayakDan · Post by **KayakDan** » Fri Jan 11, 2008 8:39 am

Paul S wrote:
Catigale wrote:Ive got a great Anchor Alarm which automatically wakes me and tells me " Honey, we're dragging"

She has many other benefits too numerous to post here.

Ive found the change in motion doesnt wake me up unless its drastic - but one thing that does wake me up is listing....as I found out at 3am taking on water....
damn u got the anchor alarm... i got the heeling alarm on our boat..at 20-25 the alarm goes off until the condition is corrected!

Ahh,but your "heeling alarm" is getting used to it,and now we're losing our competetive edge when we sail together!

Our "heeling alarm" must be defective. Last year in Maine we got whacked by a stiff breeze and the boat went over to about 30+. I said " whoa! Ease the mainsheet!"
She laughs and says"whatsa matter? you scared?"

As for my dragging alarm...it's a stern anchor!

Post by **Russ** » Fri Jan 11, 2008 9:43 am

Catigale wrote:..one thing that does wake me up is listing....as I found out at 3am taking on water....

Woah!!!

That would be frightening. What caused you to take on water?

Catigale · Post by **Catigale** » Fri Jan 11, 2008 10:21 am

See thread here

Zoran · Post by **Zoran** » Sun Jan 13, 2008 9:43 am

I thought I was like Eric until I was awoken one night by my GPS anchor alarm. Till I was awake and on deck I was already over 100 feet out of my circle heading towards one power boat, When I pulled my anchor chain was wrapped around my plow not allowing it to "bite" again. When I looked at crumbtrail on GPS it was obvious that I did many circles around anchor that night and somehow it wrapped around.
What I do is to set GPS alarm at the moment when I drop the anchor so i am in center of circle while above the anchor, than I allow for some extra length depending on situation (bottom, other boats in proximity etc.)
i still think I will have to buy extra rod for my old danford and throw two anchors whenever possible.
Zoran

Rich Plumb · Post by **Rich Plumb** » Mon Jan 14, 2008 10:41 pm

I fabricated one of these anchor alarms using a wireless door bell. I was able to find a door bell, at Lowes, for $9.95 that featured a battery powered reciever as well as transmitter. The bow switch assembly seems to work as expected, when bench tested. I'm looking forward to trying it out on the boat, this spring. More to follow.

~~~~~~~_/)~~~~~~~~~
Rich Plumb, "Plumb Crazy"
26X, Covington WA

Paul S · Post by **Paul S** » Tue Jan 15, 2008 6:19 am

Rich Plumb wrote:I fabricated one of these anchor alarms using a wireless door bell. I was able to find a door bell, at Lowes, for $9.95 that featured a battery powered reciever as well as transmitter. The bow switch assembly seems to work as expected, when bench tested. I'm looking forward to trying it out on the boat, this spring. More to follow.

I am sure you mean testing it under controlled conditions..not at 3am scrambling to not hit another boat or shore or worse! Certainly one of those things like flares you like to have but never want to use for real!

MacGregorSailors.com

MacGregorSailors.com

Anchor drag alarm + hints page

Anchor drag alarm + hints page

Paul, I'm confused, I just set my GPS to Anchor drift mode!!

I get it, that makes sense, Paul.