Anchoring problem

[Pentium7]

Hi All,

I am hoping you can help me solve an achoring problem I constantly experience. I own a 7.8 meter trailer sailer called a Ross 780, if you do a google a couple of sites will come up and show what it looks like. The problem I experience is a constant darting of the boat from side to side whilst at anchor. The movement is not a swing, more like the boat sailing off on a tack until it pulls on the chain which turns the boat and it darts off on the other tack until it pulls on the chain again, it repeats this all day and night whilst wind is about. I have 8 meters of 8mm chain out and nylon rope after that, I have tried scope from 8:1 to 4:1 to try to stop the darting. I have my dagger keel down for stability, which has a draft of 1.8meters. I have my dagger rudder down and tied off in the straight ahead position. I am usually anchored in 2 to 3 meters of depth.

Any suggestions as to how to stop this movement would be greatly appreciated.

[sailaway21]

Rig a small sail aft, off the boom or backstay, called a riding sail and that should alleviate your problem. It does not have to be anything fancy-a piece of canvas will work.

[Kacper]

Yeah - lighter boats experience that all the time. When we picnic anchor with a Capri 22' it does the same thing.

You gotta rig the riding sail amidships.

Here's a link to a picture of what sailaway is taking about:

http://i4.photobucket.com/albums/y14...c/HPIM1379.jpg

[sailingdog]

A riding sail might do it...

So would anchoring from the stern... Most modern boats will sit at anchor far better if anchored from the stern, rather than the bow. This is primarily due to the fact that most of the windage on a boat is forward of the center of lateral resistance, so the boat wants to head off.

If you're in a protected anchorage, there is no real reason why you couldn't anchor from the stern. Give it a try.

Look at this web page to see why I say this.

[CapnHand]

Originally Posted by sailingdog

If you're in a protected anchorage, there is no real reason why you couldn't anchor from the stern. Give it a try.

I was considering getting a riding sail but I'll give this a try first. Interesting web site. Thank you Mr Dog!

PS It might be a good idea to do it in an isolated anchorage as well so people don't fall off their boats laughing at me achoring back asswards.

[tenuki]

Stern anchoring also passes the 'tenuki tests', ie:

1) 'is it easier?'
2) 'does it involve me not having to go forward?' (see rule #1)

All these years I've been feeling guilty, I gotta bookmark that.

Note that the riding sail is effective by adding a 'windage feather' to the rear of the boat to conteract the smaller feather that exists at the front of the boat (mast, rigging). So a riding sail adds to the forces on your anchor while anchoring from the stern takes advantage of what you already have. Pretty cool stuff SD, thanks.

I noticed the diagrams had a bridle, anyone have something slick/clever to share other than just cleating on one side or the other or making a makeshift bridle with the anchor rode on the fly?

[Looking]

"Here's a link to a picture of what sailaway is taking about:"

Kacper... that looks suspiciously like a Bayfield '32... stuck on the brain? No worries... I have the same problem with a certain Garden Ketch.

[sailingdog]

Tenuki-

You could make a fixed bridle, by splicing three lines together via three eye splices over thimbles and a shackle. Make all three the same length, and then you can use one for each stern cleat and the third can be attached to the anchor rode via a rolling hitch. You can rotate which get used where to change the chafe points. I'd imagine three 20' pieces of line would do the trick nicely.

[soul searcher]

Only draw back to going stern to is all your hatches are now facing the wrong way. Might get a little stuffy in the v berth.

[sailingdog]

Originally Posted by soul searcher

Only draw back to going stern to is all your hatches are now facing the wrong way. Might get a little stuffy in the v berth.

Not if you leave the companionway open...

BTW, I've done this and gotten strange looks, but I'm on a trimaran, and we're generally considered to be the oddballs in the sailing community.