How do you stop yawing around at anchor?

[houldsworth]

How do you stop yawing around while at anchor in windy conditions.

A modern beamy boat with high topsides can sail around through 180deg taking a lot of room and causing excessive loads on the anchor. I have experienced this with 50m heavy chain in 10m water and 35 - 45kts wind. The anchor was well dug in but still dragged slowly across the bay, in the Med with no tides.

If one put out 2 anchors and would it be better if both over the bows as wide as possible or one bow and one stern to try and keep the boat as straight as possible into wind.

Any suggestions, please.

 

[Saguday]

Snubbers from the anchor chain to the foredeck side cleats port and starboard either side of the anchor chain so you have a sort of Y arrangement slows it down a bit and then add a small riding sail somewhere on the stern off the backstay.

Or buy a really big heavy long keel boat

 

[Poignard]

Riding sail

Have you considered a v-shaped riding sail as described by Piota some time ago on these forums?

They are also available ready made and in kit form from http://www.bannerbaymarine.com/

 

[Salty John]

In the Caribbean I routinely used two anchors from the bow, somewhere between 45 and 90 degrees apart. This was for added security rather than yawing but would probably help.
You could also try taking a snubber, 6' or so long, from chain to a deck strongpoint in the usual manner, but then drop a large bight of the slack chain to the seabed. This will act as a drag, preventing the bow from moving so easily. Don't do it in coral, though, it can damage the seabed.

 

[shmoo]

Although I am sure the delta style riding sail mentioned above would be better, because we are lazy and mean we have not got around to getting one yet and use an old sailing dinghy jib from a boat jumble. Run it up the back stay using the main halyard and sheet it to, say, a hand rail on the coach roof. Needs sheeting in very hard but is still bi-modal - i.e. fills out one side or the other. A lot better than no riding sail at all though.

 

[stevepick]

A bucket

I find hanging a sturdy ships bucket (with steel handle) over the stern on about 2-3 m of line really damps down my AWB yawing at anchor. I do have a riding sail to rig up the backstay , but find the bucket is easier and less faff to set

Steve

 

[snooks]

If you're going to be there for any amount of time....Inflate the dinghy, tie warp from kedge to the back of the boat, stick the kedge in the dinghy (along with the oars pump outboard lifejactes etc), let the wind blow you down wind 3 or 4 boat lengths, drop anchor, row/motor back.

Take up the strain using your main winch, rig a bridle (another bit of rope with a rolling hitch) job done.

If it's a short term anchor waiting for the tide, you could just use the time to charge your batteries and run the engine in tick-over astern

 

[HoratioHB]

I had a riding sail made up which went up the topping lift and sheeted towards the front of the boom, it worked brilliantly but stopped the wind generator from working!!. Took advice from this forum last year and developed the 'large bight behind the snubber' technique as espoused by Salty John. However if you drop it onto the sea bed even on sand it rumbles away and if you sleep up forward is a pain. However even if you make the bight just short enough to keep clear, it works really well in two ways. Firstly the added drag at the bow reduces the tendency to yaw and secondly you add a lot more weight to the scope to keep the anchor angle low rather like those weights some people slide down the anchor line (can't remember what they are called). You need a fairly long and springy snubber for this to work - I use 5 metres of nylon. This is especially handy if the anchorage is crowded and you can't put out all the scope you want - anchor cable does nothing if it is in the locker.

If you do want to use a stern anchor, they are really great and can also be used to hold the boat into a swell to stop rolling. However I have seen boats put them out without telling/asking the neighbors and then one boat stays stationary while all the others are still swinging around which can cause some interesting issues. if I do it I always make sure I am well clear or tell boats next to me what I intend to do.

I gave upon two anchors as they are not of the same type and use different line - one on 10mm chain one on 8mm chain and then nylon in my case. It then becomes almost impossible to share the load. The second anchor then becomes insurance should the first one drag, thats fine, but in a crowded Caribbean anchorage (all of them!) you will probably hit someone before the second anchor takes up the slack and even you don't you will still have to move and that then means pulling up two of the things with only one a windlass, probably in the middle of the night in squall etc etc. Oops sorry - didn't mean to wander off into an anchoring thread. I'll get me coat.

 

[Poignard]

Horatio said: "I had a riding sail made up which went up the topping lift and sheeted towards the front of the boom, it worked brilliantly but stopped the wind generator from working!!.
----------------------------------------------------

You'll be wanting to sell it perhaps?

 

[lw395]

I find hanging a sturdy ships bucket (with steel handle) over the stern on about 2-3 m of line really damps down my AWB yawing at anchor. I do have a riding sail to rig up the backstay , but find the bucket is easier and less faff to set

Steve

As I tend to anchor using a lot of rope and relatively little chain, I am a fan of a weight on the anchor rode, just far enough from the boat not to hit the seabed. As well as reducing snatch and increasing the holding of the anchor, I've found this to improve yawing as well.
Not sure exactly how it works, but could be to do with the rode going more vetically down fro mthe stem. I used about 12kg of lead on my 39ft boat fwiw. Must point out that I'm not a truly hardened heavy weather anchoring type, being exposed to F7 or more at anchor would seem bad planning to me, especially when I tried to justify it to swmbo. Of course other people operate in different circumstances.
The bucket is worth a try, damping or removing energy from an oscillation is always a good way to stop it building up.

 

[DaiB]

Springy line

I use a 12m length of 14mm nylon and a chain hook. Let out the chain to the scope I need minus 12m, attach the chain hook and line and let out the chain so it is slack and the weight is on the nylon line. The nylon line absorbs the surge as the wind swings the bow. It really helped on our boat and I estimate it reduced the yawing by half.

 

[BlueSkyNick]

I see you have a Dufour - maybe with inmast furling? If so, you could try letting out a small amount of mainsail which would act as a riding sail to some extent.

If slab reefing, try something similar with some sail ties to provide a 'very deep' reef.

 

[electrosys]

How do you stop yawing around while at anchor in windy conditions.

A modern beamy boat with high topsides can sail around through 180deg taking a lot of room and causing excessive loads on the anchor. I have experienced this with 50m heavy chain in 10m water and 35 - 45kts wind. The anchor was well dug in but still dragged slowly across the bay, in the Med with no tides.

If one put out 2 anchors and would it be better if both over the bows as wide as possible or one bow and one stern to try and keep the boat as straight as possible into wind.

Any suggestions, please.

As crazy as it might sound - if your set-up permits it, try anchoring from the stern. You will no doubt encounter a fresh set of problems, but hunting around the anchor will stop.

 

[dovekie]

Yawing at anchor

Just to pass on our experience:

20 knots of wind.
No riding sail, 70-90 degrees of yaw.
Flat riding sail, 50-60 degrees of yaw.
Vee-shaped riding sail (as per Piota on this forum), less than 10 degrees of yaw.
Longish fin keel yacht with plenty of windage forward in the form of two rolling headsails.

 

[boatmike]

Take up the strain using your main winch, rig a bridal (another bit of rope with a rolling hitch)

I think you will find a bridal rig is a permanent hitch....... a bridle on the other hand is two ropes attached usually on either side of the boat/horse w.h.y. coming together at a common point (in the case of a horse its usually in the gob area.....)

 

[snooks]

I think you will find a bridal rig is a permanent hitch....... a bridle on the other hand is two ropes attached usually on either side of the boat/horse w.h.y. coming together at a common point (in the case of a horse its usually in the gob area.....)

Thanx, spelling has never been my strong point, which is why I went into photography

 

[TonyS]

Big ships do it too!

I was watching a naval destroyer and a cruiser at anchor in F7/F8. Both yawed through a large angle (more than 90 degrees). The period of the yaw was longer for the cruiser and could be measured in minutes. The destroyer yawed about twice as fast. Can a physicist now give us a formula to calculate the yaw frequency and amplitude as a function of the wind speed? PS Don't both have long keels?

 

[jimbaerselman]

Stopping yawing

Yawing happens when the boat's centre of windage is forward of the point of lateral resistance in the water (usual). This causes a little yaw to develop whenever there's slack in the rode and there's enough wind. Critical wind strengths when yawing starts depend on how big the distance is between centres - anything from 15kts to 25kts can start things going.

The boat then literally sails off sideways until it's yanked round by the anchor rode. Solutions are either to shift the balance of windage and water resistance, or nail the boat's position down, or bias the windage, or make the anchor rode bite sooner. Damping the oscillation (chain on ground, chums) may make the boat tolerate slightly more wind before it starts oscillating, but once it's going, it has little effect.

Solutions:

1. Buy a long keel ketch instead (shift balance)
2. Tie stern to shore, be it a quay or shoreline (nail).
3. Use a second anchor astern as a substitute for the shore (nail - unfriendly to neighours).
4. Anchor by stern instead and accept that slapping sound (shift balance)
5. Give the stern of your boat a lot more windage (shift balance)
6. Move your keel forward (shift balance - a bit radical)
7. Take a new slant . . . attach snubber 10m down chain, and bring it to the stern, so you're permanently anchored on one tack - kiting (bias)
8. Forked moor - 2 anchors - far more secure anyway (bite sooner).
9. Buy a catamaran - support the rode through a long bridle (bite sooner)
10. Tidal moor - confuses your neighbours! (nail)

Sadly, not all these solutions work for all boats . . .

That should keep Bilbo yawning though.