Wandering at anchor

[magnetic]

Saturday night, out in Tolo Harbour, anchored off Centre Island in about 4 meters with an incoming tide and a light F2, and I decided to leave the GPS on, tracking on 8 metre resolution.



The result over 6 hours was fascinating - a perfect crescent traced out downtide of the anchor. I was so intrigued that I watched what was going on in great detail - in fact, the arc of movement was so extreme (about 135 degrees) that I thought I either was or was about to drag the anchor out. I didn't. and this is what I observed -



The Mac responds to whatever element grabs hold of it first (wind or tide) and once the bow has nudged an inch, a turn sets in, causing the boat to sail at anything up to 2 knots through an arc across the current/wind. As the anchor rode (I was using about a 5 to 1 scope) tightens, so it pulls the bow around, and the process starts in reverse - a rapid tack, followed by a run then a reach then a point up into the wind/tide, then followed by another anchor-induced tack. Quite smooth, not at all scary, and as smooth and rhythmic as clockwork. It sure as h#ll takes some getting used to though



NB Note the Patent Pending Asymettrical Lazyjacks

[FAAbaddog]

Magnetic,

Add this (at least it works very well for me) and reduce your swing to less than 45 degrees:

http://www.sailrite.com/Anchor-Riding-F ... -5-Sq-Feet

JMHO!

BADDOG

[magnetic]

Hi - yes, I had looked into this, but the driving force on Saturday night was the incoming tide rather than the wind.



When she's on the mooring I swing a 5 gallon bucket made off to 2 large warps tied to the stern cleats, and although this slows her down a bit, she still wanders more than the other boats around her

[Russ]

Tide was causing this?

Were your boards down?

[magnetic]

rudders but not daggerboard because of the noise

[uanhanlouee]

All boats hunt. The currents below and wind directon above changes all the time. If you want to keep it pointing in one place you need a stern anchor. it's only way to fight nature. Only way to anchor in many ;places.

[magnetic]

all boats hunt

she still wanders more than the other boats around her

sorry, maybe I didn't make that clear. A stern anchor is a very questionable tool when faced with a significant rising tide - in this case 2.3 metres - though, to be frank, neither wind nor tide was changing all the time and conditions were fairly predictable last weekend.

On a similar note, in Typhoon-ridden Hong Kong, a fixed fore-and-aft trot mooring would be suicidal. As you can see from the last photo, we are all on swing moorings; it's just that my swings far more than the others, hence the use of the "sea anchor" bucket off the stern. I think it's probably just a feature of being tall and shallow, rather than squat with a deep fin keel and consequently low centre of gravity. It's still entirely safe, and at least I get to see more of the scenery

[mk1]

I usually drop the rudders half the way to reduce swing at anchor. Usually I get it under 90 deg, but it is still more than other boats. Probably not a good idea in a strong wind. Tried dropping the centerboard, it makes it worse. too much of freeboard could be a bad thing. I will try a bucket next time. Seems like a good idea.

[Sumner]

We have only anchored by other boats on a couple occasions and everyone probably knows this, but don't assume that all boats will swing in unison. They can still hit each other if the rodes are long enough and they end up swinging towards each other.

Now we were anchored a couple times where there were also tides and we all seemed to swing in unison there depending on the direction of the tide, but then throw in wind if there is any and you can get all different combination's of swing and possibilities of hitting each other.

We were anchored on the gulf side of Marathon by two little, little keys and on a Bahamian moor so that we wouldn't swing into the entrance of a marina nearby. A big cat came right up behind us and anchored and I yelled back at them that we were on two anchors and wouldn't be swinging. He then moved back aways from us and all was good,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

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[Mac26Mpaul]

THe tendency at anchor, to dance about all over the place relative to other boats, is for me, the only major negative of this boat! There are some tight anchorages where I am, and I'v come close to disaster several times now..... Its just downright annnoying and often means, we cant, anchor with the other boats, (which often means being in a not so sheltered area, or being quite a way from the beach - not fun when you have to row an overloaded 6 foot fibreglass dinghy there )

To be honest, I was actually considering selling the boat because of it, but then the missus piped up and said, there is no way she is going back to some full crouching headroom, uncomfortable as h*ll smelly old trailer sailer. I'm glad she took that attitude, because I reckon I would have been kicking myself if I went back that way too

And so, we learn to live with the Mac dance...... Is there anyway to use an anchor sail on the M? I mean, no backstay, so how would you rig it?

[Sumner]

.... Is there anyway to use an anchor sail on the M? I mean, no backstay, so how would you rig it?

We have a double block at the top of the mast of our S. One line through it is our topping lift and the other is to pull the anchor sail up the backstay. You could have about the same and swing one into place and cleat it off and run the anchor sail up it and use the second to pull the sail up.

One nice thing about our boats is that it is so easy to get to the top of the mast to work on it ,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links

[FAAbaddog]

THe tendency at anchor, to dance about all over the place relative to other boats, is for me, the only major negative of this boat! There are some tight anchorages where I am, and I'v come close to disaster several times now..... Its just downright annnoying and often means, we cant, anchor with the other boats, (which often means being in a not so sheltered area, or being quite a way from the beach - not fun when you have to row an overloaded 6 foot fibreglass dinghy there )

To be honest, I was actually considering selling the boat because of it, but then the missus piped up and said, there is no way she is going back to some full crouching headroom, uncomfortable as h*ll smelly old trailer sailer. I'm glad she took that attitude, because I reckon I would have been kicking myself if I went back that way too

And so, we learn to live with the Mac dance...... Is there anyway to use an anchor sail on the M? I mean, no backstay, so how would you rig it?

Mac26Mpaul,

I attach the anchor riding sail to the topping lift line that goes from the end of the boom to the top of the mast, snap shakle to the end of the boom, snap shakle off the main halyard, and then a line to the boom vang tackle.

Works like a glove on a chicken

BADDOG

[NiceAft]

magnetic,

I would like to see a photo of what you saw on your screen. If you decide to replicate your experiment, please take a photo and post it.


Mac26Mpaul said:

Is there anyway to use an anchor sail on the M? I mean, no backstay, so how would you rig it?

Yes there is.

An anchor sail is attached at three points. To do this on an M you use (a) the topping lift [if you have one], (b) the two aft cleats, (c) the base of the mast. An ancor sail's effectiveness increases the farther astern you rig it.

Ray

[Catigale]

I cut the arc swing of my in half, down to about 60-70 degrees, by dropping a mushroom anchor of the transom - cleated to an added cleat low on the transom. You have to adjust it a bit for tidal range above 3 feet, but it is really easy to deploy.

[Sumner]

I cut the arc swing of my in half, down to about 60-70 degrees, by dropping a mushroom anchor of the transom - cleated to an added cleat low on the transom. You have to adjust it a bit for tidal range above 3 feet, but it is really easy to deploy.

Is it dragging on the bottom or just in the water? Not sure what you meant about the 'adjust ...tidal range'?

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

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