Swinging at anchor

So I pulled into Marsh Harbor to anchor out today. Wife and one son need to fly back tomorrow. Anchored out with about 8 other boats-- all sail boats.

Why is mine the only one moving all over at anchor? I have a paddle board on the bow. Also have a snubber set but maybe not correctly.

Look perfectly still to me.

Is it possible that a current is affecting your anchoring spot differently than that of others in the area. It doesn't look like you're anchored in among a crowd.

The paddle-board shifts your above-water profile further forward, but not enough (I don't think) to offset the windage of that aft deckhouse.

Maybe ease out some more scope and see what happens?

Can you unroll a bit of main sail to keep it pointed into the wind?

I have noticed the same thing when I anchor next to a sailboat.

I think that t comes down to the fact that they probably have a gigantic keel coupled with lower windage.

MRRiley said:

Can you unroll a bit of main sail to keep it pointed into the wind?

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Judging from the profile drawing in Cardude's avatar, it appears that a bit of main would still lie at or forward of the boat's aerodynamic center of effort. Ketches and yawls have this easier - a bit of mizzen settles things right down.

MRRiley said:

Can you unroll a bit of main sail to keep it pointed into the wind?

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I was wondering about doing that. Would probably flap like hell however.

ksanders said:

I have noticed the same thing when I anchor next to a sailboat.

I think that t comes down to the fact that they probably have a gigantic keel coupled with lower windage.

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This is probably the case. I do have more windage and I'm sure less keel than these other boats.

I probably need to let out more scope as well.

I suck at anchoring.

If your anchor line is not in line with the boat centerline, the wind will push it to one side. Do you use a bridle ?

I still am not used to how much my boat sails at anchor compared to my sailboat. As others have said, it is a combination of greater windage and less keep and rudder. A sailboat has a much larger keel and most will have a fin keel and spade rudder. These are going much deeper in the water limiting movement.

More scope may help, but I doubt it. I am sitting at anchor myself right now and am swinging back and forth much more than the sailboats around me.

ksanders said:

I think that t comes down to the fact that they probably have a gigantic keel coupled with lower windage.

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Indeed the size of their keel make them far less prone to swing under wind. They roll more but swing less.
One owner of my marina has a sailboat transformed in trawler (removed the mast and use it has a trawler), his gigantic keel allow him to go straight, and even in reverse, under moderate wind.

L.

Swinging at Anchor

Sydney has mooring areas catering for sailboats and powerboats, it is recognized that sailboats and powerboats swing differently, space has to be allowed for that to happen to avoid collisions.
At first I was thinking you were inviting over guests from the sailboats to enhance the swinging....

We used to have a Catalina 42 sailboat. It would sail at anchor so much that sometimes I thought it had decided to sail out of the anchorage.

I wonder if your rudder hard over to one side or the other make a difference ?

Ours dances a bunch at anchor . My old islander sailboat always pointed to wind , hardly moved at all . Cardude I guess you know you've cause me to start thinking about a salty sailboats again.

Benthic2 said:

I wonder if your rudder hard over to one side or the other make a difference ?

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I just realized I didn't lock my rudder.

Also, my snubber is just a single line off to one side of the chain and not set up as a bridle. Maybe that makes it worse.

Anchoring is hard....

I think having the attachment point of your anchor along the centerline of the boat will help to minimize swinging.

Make a checklist while it's fresh in your head. It'll help the next few times until it becomes second nature.

Pack Mule said:

Ours dances a bunch at anchor . My old islander sailboat always pointed to wind , hardly moved at all . Cardude I guess you know you've cause me to start thinking about a salty sailboats again.

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I'm having so much fun trying to learn how to be a sailor.

But the power boater still comes out. I beat a regular sailboat into this anchorage today-- he had a small engine I guess. ��

Benthic2 said:

I think having the attachment point of your anchor along the centerline of the boat will help to minimize swinging.

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OK. I guess I need to rig up a real bridle.

cardude01 said:

I was wondering about doing that. Would probably flap like hell however.

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Use the traveler on the boom and sheet it to the windward side. Kind of though you are "hove too" while underway.

Another thought would be to use some sort of drogue off the stern. A bucket with holes perhaps? Coffee can etc. You want to be able to recover it without too much effort but it would act to keep the stern, at least down current.

Good thought, Riley. I have one of these onboard for fishing. I use it to align with the current when the wind is blowing me caddywompass.

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You could try a steadying sail.

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Can't help as never having the problem. My trawler has a keel and the tidal currents have the most effect, otherwise it's the wind. Having an all-chain rode probably helps. On the other hand, my previous vessel (small sailboat) with a mostly nylon rode had no issue either.

As long as it is not causing your anchor to unset and drag I would suggest accepting that your boat will sail around constantly at anchor, and moving on with your life. Forget about dragging extra stuff behind the boat, you will forget about it, back over it, foul your prop, have a terrible day. I have not found using a bridal, to both sides of the boat, or having the snubber go directly over the bow to stop either of my last two boats from sailing back an forth at anchor.

Use a Bahamian Moore , 2 anchors one fwd one aft lead to the bow.

Your high windage boat will still dance about , but mostly in one spot.

When aboard a spread of anchors from the bow will steady the boat , but a major wind shift could be a problem when absent.

cardude01 said:

OK. I guess I need to rig up a real bridle.

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In my experiences and what I have read, to help prevent swinging, you use a bridle but with uneven legs.

With the attachment point right in the center, the wind can get to either side and the tiniest push stats the back and forth. Once itvgoes to the farthest point, it now has the momentum to get not only to center but beyond. Andvthen it starts all over again fartherst point to farthest point. By offsetting the bow with unequal legs, you stop some of the swings entirely and make the swing to one side less (at least in theorry....but I too have noticed less to that one side in real life).

So try a bridle both ways and see what happens. Just use a coupke dock lines to see if the bridle helps, but if only the uneven legs help, and no better than your current setup, then a riding sail or a drop weight (similler to a sentinel/kellet) off your bow might be the next moves.

I tried everything on our sailboat to stop the swinging. Drogue hanging from the stern, drogue hanging from the bow, spare anchor on a short scope hanging from the bow, spare anchor on a long scope from the bow, spare anchor on a short scope hanging from the stern, spare anchor on long scope from the stern, steadying sail, unequal bridle lines, snubber attached to the tow hook on the bow, reduced scope, extra scope (and, we had an all chain rode), rudder straight, rudder hard over. Some things mitigated the swinging some, but nothing stopped it.

After a while, I just decided that it wasn't hurting anything and just let it do what it wanted to do.

Two things to try:

Spring the rode. That is attach a line from the rode to a side cleat to hold the boat offset to the wind.

Add windage aft and reduce windage forward. The boat sails around because it is nearly balanced regards to wind forces. You need to unbalance it by adding wind load aft.

Underwater profiles will make boats lie differently to the current but usually they are steady.

BruceK said:

Sydney has mooring areas catering for sailboats and powerboats, it is recognized that sailboats and powerboats swing differently, space has to be allowed for that to happen to avoid collisions.
At first I was thinking you were inviting over guests from the sailboats to enhance the swinging....

Click to expand...

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