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This could be the mother of all stupid questions but is it possible to have too much scope when anchoring? Could this lead to poor anchor performance or is more better?

Jim

Since nobody has chimed in yet I will take an attempt at sticking my foot in my mouth.

I have very limited experience anchoring but from what I have read on this site the can swing pretty good while anchored so if you don't do something about the swing you may actually sail back and forth on your rode...the more rode the bigger the area you may sail.

There are threads on making a simple anchoring bridle. Personally I have set a second anchor off the stern which worked okay but could be problematic if the tides or currents will swap directions or if a wind change happens.

But if you got lots of room...

I will be quiet now and let those with much more anchoring experience chime in.

Good Luck,
Jim

Never a stupid question and especially with something as important as anchoring.

General rule of thumb is more is better.
Standard rule is 7 to 1, so for every foot from the anchor on the bottom to the deck cleat your should have 7 feet of rode. I'm assuming you are using some form of traditional anchor (danforth, plow etc.)

There are other considerations such as chain. Ideally, 100% chain would be best, but realistically who can handle the weight and storage of that much chain. So make sure you have chain attached to your anchor and wire the shackles shut so they don't work their way loose.
Anchoring techniques

RE: Swing (sailing on anchor) is an issue for Macs, but mostly an annoyance.

--Russ

The scope you use depends on many factors, including sea state, depth, bottom type, type of anchor used, is the tide in, or out, tidal range, crowding in the anchorage, etc. Generally, if you set your scope at 7:1 for max tide in your area, you will be fine. Too much scope and you can swing into another boats swing area. If you are in a deserted anchorage and are unsure, more is better.

~Rich

Thanks for the replies. My question emanates from attempting to anchor in some mud. What was interesting is that the anchor (Guardian G-11) seemed to grab much better on a shorter scope.

Just the wind drug the G-11 easily - winds were around 10knots. I had originally purchased the G-16 being the more is better kind of guy that I am but it did not fit in the anchor locker. My thought is that the G-11 may not be up to the task and may be better used as a stern hook for crowded anchorages in the party places. I probably need to give it a better chance in some sand as it brought up some serious mud where I was at.

Not sure if I want to go to a G-16 (or a Fortress), a Manson Supreme, Delta or a Claw for the primary. The thought of having to install a new anchor pulpit is not real attractive.

Jim

jschrade wrote:Thanks for the replies. My question emanates from attempting to anchor in some mud. What was interesting is that the anchor (Guardian G-11) seemed to grab much better on a shorter scope.

That's unusual. Fluke style anchors always do better with a lot of scope and a big angle.
There are lots of factors. One of the biggest factors I've seen is poor technique. I don't know how many times I've seen a yahoo pull into an anchorage, toss the anchor over the side, tie it off and call it good. The rode/chain gets tangled up and they wonder why it's not holding.
For most anchors (like yours) you need to lower it to the bottom and then back off while paying out rode. Gently snub it up once the scope is adequate to dig it in and set it. The harder you pull, the deeper it will sink in.

Also remember that the more rode you have out the more "spring" will be felt like a giant rubber band. This is a good thing as it absorbs the tension so the anchor doesn't get yanked out.

The way you remove a deeply set anchor is to reduce the rode to as closet to 90 degrees up and down over the anchor. Often the bouncing will lift it out, otherwise drive over the anchor to lift the flukes out. It will be very muddy.


--Russ

I'd go along with the others that it is hard to get too much scope, but on this night in little to no wind the scope gots us into trouble......

http://purplesagetradingpost.com/sumner ... ll-09.html

This night a stern line to shore almost got us into trouble.....

http://purplesagetradingpost.com/sumner ... -koot.html

And on this anchorage a stern line got us into a lot of trouble....

http://purplesagetradingpost.com/sumner ... ll-09.html

So far we have either been anchored out every night or tied up onto the beach. At this point we have spent a lot of money on our anchor and shore lines and we don't regret one penny of it. Who knows what the wind is going to be like at 2 in the morning, so try and prepare for the worst when you tie to shore or anchor or both. I won't run an anchor line or shore line off of both the bow and the stern any more unless I'm darn sure the wind is going to stay down overnight. If the wind shifts and comes into you on your beam you will get tremendous loading on the lines/anchors and the boat will try and roll side to side into the wind. Light wind is not bad, but if it starts getting over 20 knots you won't feel very secure.

At this point we have the orginal Danforth that came with the boat, a Fortress FX-11 that we have never used, a 22 lb Bruce that has been our main and only anchor used since after our first trip. On that trip we used the Danforth in mud with no problem, although I think we drug a little one night. Recently we added a 25 lb. Manson Supreme as it is suppose to be even better than the Bruce. The Bruce has never drug in all the nights we have used it, but that has been in western lakes with pretty much rock bottoms. All of our rodes are 200 feet plus the chain, 20 feet of chain on the orginal anchor and 30 feet of 1/4 on one other and 5/16 on the last rode. I'd give equal credit to having at least that much chain out as to the anchor design. The chain will get the line down and lower the pull angle. That will be equivalent to using more scope with less chain. Two rodes have premium 3/8 3 twist line and one (for the Manson) is 7/16 3 twist and the chain on that one is also the heavier one. This will be our go-to anchor in a really bad situation. We will continue to use the Bruce most of the time.

The scope is normally measured from the bottom to the waterline on the boat and you have to add some for the height of the line above the waterline where you are attached to the boat. When anchoring Ruth gives me the dept reading and I multiply it by 10 and put out that much line and the chain is a bonus. I then try and make sure we won't swing into land with that much rode out. So far that has worked great and it sure is nice feeling that you are pretty safe in the middle of the night when the big storm rolls in. Hey if you got the line put it out there within limits .

At present we also have 800 feet of premium 3 twist shore lines. 600 feet of 3/8 inch and 200 feet of 7/16 that could go on an anchor rode. At Lake Powell 200 feet won't always.....



....reach a place to tie to and the lake can be a couple hundred feet deep 30 feet off shore. On our first attempt to go there (Jeep motor blew up) we almost went out there with cheap yellow poly line. That would of been a serious mistake. Your lives, your boat and all of your equipment are depending on the anchor and shore lines. Not a place to be cheap in my point of view.

Here is how I now mark our rodes so I can tell how much I have out.....



http://purplesagetradingpost.com/sumner ... ing-4.html

....it is much easier than stopping and trying to read a number off of a single tag as you play the rode out. You know where you are as the line streams out of the anchor bag.

Get good stuff, use it the best way you can, and hopefully never have a "major" problem. We have had problems on anchor, but we will still anchor out every chance we get. Nothing like being out there by yourselves if you like that kind of thing and we do .

c ya,

Sum

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I have always used between 7:1 and 4:1, depending on the wind and weather. The other thing to consider on the ocean is the tidal range which makes a big difference how deep you anchor in the first place and how much rode you allow. You need to allow for the change in dept due to the tide which can easily be 15 ft.
I remember anchoring in the middle of the night at high tide using the dept sounder and chart as a guide and waking up in the morning to find I was surrounded by a sea of eel grass.I just happened to pick a spot where a channel ran into the mud flat,when I anchored it had been 30 feet. When the tide changed and the boat swung with the tide I ended up sitting in the channel with a couple of feet under the keel and mud flat on both sides of the boat.

The 7:1 rule of thumb is good for general anchoring, but in stiff winds, 10:1 is what is recommended.

The bridle is one way of preventing the swinging at anchor which has been mentioned. I use an anchor sail. The one I use is designed for boats up to 32 feet without a back-stay.

Ray

JIm

Not a stupid question at all. I asked a similar question on this board about 5 years ago about anchoring - most texts recommend you set the anchor then LET OUT the rode to the recommended scope.

I always thought it would be better to set the anchor on a long scope, then SHORTEN the rode. My theory is, that the longer scope gives more setting power (more horizontal force)...physics would support this side of course.

>Ive done it both ways on Cuttyhunk for a week, but haven't dragged either way. Of course, thats my Bullwaga in mud, which is really good combo.

One of my favorite spots to overnight gets quite crowded this time of year. The bigger boats with all chain rode go with a very short scope to minimize swing. I get nervous so I try to pick a relatively wide spot and go 5:1 minimum, then use a bridle to minimize the swing. Not too long ago I was out and one of my "neighbors" apparently didn't like my longer scope and moved in the middle of the night. I thought it was funny since I triple checked to make sure our swinging arcs didn't intersect.

The way I create a bridle is to tie a double figure 8 knot (truckers hitch) in the main rode. Then I run a secondary line through the loop I just created, outside the stays to the winch, and haul that line in until the boat stops swinging so much and is in line with the others in the anchorage. I'd like to replace that with a rope climbing "rescue 8" but I haven't found one I'm willing to pay for yet. So far the trucker's hitch works and I've only had a problem untying it one time (in heavier seas).

Seems like having the boards down helps too so I leave the motor and both rudders down when at anchor. When we're awake I drop the keel but I raise it when we sleep, the banging is too annoying.

Sometimes I'll throw a bucket off the stern and tie it off to a rear cleat as a make shift sea anchor. That helps cut down on the swinging too.

I'm thinking about taking one of my old Venture sails to the local sail loft and seeing if they can cut it into an anchor sail for the X and maybe make a boom tent out of the rest.

Last year, with two weeks' worth of nights at anchor, left me believing that Bossa Nova would do her little "anchor samba" no matter what I did about it. An anchor-riding sail, like the one in Ray's photo, helped some. A bridle helped some. But she's gonna dance.

My "best bower" anchor, as Captain Hornblower would style it, has 30 feet of 5/16" chain and 150 feet of 1/2" Yale Brait line as its rode. Overkill, probably. I figure the 30' chain is equivalent to a 7:1 scope from the bow-cleats to the waterline, and I marked the line every 15 feet to represent approximately 2 feet of depth at 7:1 scope. (I usually anchor in 8 to 10 feet depth, so it works out well for that.)

It takes me 15 to 20 minutes to set my anchor, from dropping it to shutting down the engine. I start by dropping enough chain for the anchor to reach the bottom, and I pay out the rode slowly while the boat drifts back from it. I'll put a little strain on it when I reach approximately 4:1 scope, just enough to "encourage" the anchor to straighten out and set; then I'll let the rode go out to 7:1, put a strain on it again, and cleat it down through the Skene chocks I've installed outboard and forward of the anchor cleats.

Then I'll set the engine to about 1000 RPM for a minute or two. While it's running, I go up to the bow pulpit and feel the rode to be sure the anchor isn't dragging; if it is, I'll go through the chore of re-setting it. If it does OK at 1000 RPM, I'll go to 1500 and check it again - then 2000, check again - then 2500 and check again. Then I'll ease the engine down to idle, enough to avoid the rubber-band effect of that stretched nylon rode ... and finally shut it down, then set my GPS to "anchor alarm mode" and turn on the bread-crumb trails.

Next morning, it's a heck of a job getting the hook out of the Chesapeake mud. It can take me 15 minutes or more to RAISE the anchor, and the chain is all mud. I figure that I must be doing an OK job of setting the anchor. Your mileage, of course, may vary....

Rick,

This is what I use for when the anchor does not want to come out of the mud.


I first saw it used when I was fishing in the Keys. It sure saves your back. On mine, the round metal ring is no longer round. The force of its upward pull has made it elliptical.

Ray

Ray, that anchor sail is nifty.

Glenn

NiceAft wrote:I use an anchor sail. The one I use is designed for boats up to 32 feet without a back-stay.

Ray

Where did you get it? Do you have a photo of it. This photo appears to be attached to a backstay which we M owners don't have.

--Russ