Anchor chain catenary is real

[Dockhead]

Originally Posted by Auspicious

The challenge of a riding sail is that you are balancing increased windage with better weather vaning.

Anchoring out in heavy weather, including named storms, I have taken reducing windage to an extreme. I strip my dinghy, let some air out of the tubes, and pull the plug. The mostly sunken dinghy acts as a sea anchor and reduces yaw substantially. It takes me about an hour to get the dinghy empty, pumped up, and clean with the engine and other gear back aboard.

Originally Posted by Auspicious

I left out, get the jib off the furler. That has a huge impact on yaw.

Yeah, I think that's all correct, and I'm right with you on windage. I would not rig a riding sail in a named storm.



I'm a bit of a windage freak anyway - no dinghy in davits, no solar, no bimini, no wind generator, no radar pole, no arch, liferaft out of the wind in a special locker, etc. etc.. Windage is the enemy of sailing, and I love to sail.


I've never pulled the jib down at anchor, but I'm sure you're absolutely right about that.

[Auspicious]

Originally Posted by Dockhead

I'm a bit of a windage freak anyway - no dinghy in davits, no solar, no bimini, no wind generator, no radar pole, no arch, liferaft out of the wind in a special locker, etc. etc.. Windage is the enemy of sailing, and I love to sail.

I've never pulled the jib down at anchor, but I'm sure you're absolutely right about that.

I've only pulled the jib down at anchor for hurricane prep. It's not a regular thing like, say, rigging a snubber. (N.B. I have a warped sense of humor and am teasing; if I give offense just say so and I'll stop.)

I did find on one unpleasant trip with staysail and double-reefed main that dropping the jib off the furler (an exceedingly sporty exercise single-handed - I'm glad to have a sail locker under the v-berth I can stuff a sail into through an oversized hatch) got me almost 15 degrees of pointing. I was really impressed. I spent an hour thinking about the process of getting the jib down. It wasn't any fun at all and took nearly two hours. Some of the time was because I decided to stow my glasses rather than risk them - I can't see at all without glasses.

My wife has promised to divorce me and then kill me if I ever go offshore alone again. I believe her.

[Jim Cate]

My wife has promised to divorce me and then kill me if I ever go offshore alone again. I believe her.

If you really love her, you could point out that if she kills you first she'd save the divorce lawyer's fees!

Jim

[Auspicious]

Originally Posted by Jim Cate

If you really love her, you could point out that if she kills you first she'd save the divorce lawyer's fees!

Jim, If you really love Ann you know that the only appropriate response when you have pissed her off is NOT to parse her sentences but "Yes dear."


*grin*

[Jim Cate]

Originally Posted by Auspicious

Jim, If you really love Ann you know that the only appropriate response when you have pissed her off is NOT to parse her sentences but "Yes dear."


*grin*

After living together on a boat for 33 years now, I've obviously worked out a survival plan... but your generic advice is spot on.

Jim

[a64pilot]

For me a riding sail does pretty much nothing at all. What does work though is a spring line attached about 30’ or so in front of the boat to the anchor chain and led back to one of the sheet winches. I use a sheet winch as it’s adjustable that way. If I did it enough so that I had the length figured out the midships cleat would be just as good.
It doesn’t take as much laying into the wind as you would think to completely stop the yawing.
If you look at the way the Pardey’s say to rig a parachute anchor, it’s the same way, and I assume accomplishes the same thing.

[thinwater]

Originally Posted by a64pilot

For me a riding sail does pretty much nothing at all....

There are many types of riding sails and several ways to rig them. Some really work, and some really do not. So that we can learn...


1. What style? A traditional flat triangle rigged to the backstay?
2. Rigged fore-aft, or rigged at an angle to one side? How much angle?

[Dockhead]

Originally Posted by thinwater

There are many types of riding sails and several ways to rig them. Some really work, and some really do not. So that we can learn...


1. What style? A traditional flat triangle rigged to the backstay?
2. Rigged fore-aft, or rigged at an angle to one side? How much angle?

FWIW, I use an old trysail from a much smaller boat, rigged to the backstay, and sheeted off via a turning block not fore and aft, but at a shallow angle.


Works brilliantly on my boat.


However, it's more trouble than an anchor spring line, so mostly I use that.


But below say 25 knots I don't really need anything at all; this boat doesn't yaw much at anchor (in contrast to the previous one). This boat has a shorter, bulb keel and the previous one had quite a long fin keel. Possibly the center of lateral resistance was further back on the old boat.


A64 has an Island Packet with a long keel; maybe that affects this behavior.

[a64pilot]

Originally Posted by thinwater

There are many types of riding sails and several ways to rig them. Some really work, and some really do not. So that we can learn...


1. What style? A traditional flat triangle rigged to the backstay?
2. Rigged fore-aft, or rigged at an angle to one side? How much angle?

It’s the sailrite kit, purchased for as much as anything to give us a project so we could learn the machine some, if they had sizes it would be the big one. I don’t remember if there were sizes or not.
It was a good complete kit if memory serves.
I have split backstays, so I put it of course on on backstay and then take the front line at an angle to other side of the boat, it’s my understanding that they work by putting a lateral force on the boat and not like say a vertical stabilizer on an airplane that works by being streamlined.
But I’ve tried rigging it different ways and it just doesn’t seem to do much.
I also have a lot of windage on my boat, most of it aft of course with Solar which I think is very little windgate, but the dinghy and davits have to be some, but as they “hide” behind the cockpit I don’t think it’s as much as you May think when the wind is straight ahead as in anchoring, but of course becomes real significant under sail.

And yes, it’s only in higher winds that yawing actually occurs, likely 20 ish kts or so.
Real high winds and the yawing seems to stop even without the riding sail, but I have thankfully never sat out real hurricane winds at anchor, probably mid 40’s has been the max for me.

[MicHughV]

I think much depends on the type of boat you have.

My first boat, A Roberts 38, ketch-rigged, lay at anchor, rock-steady in any breeze, no furling sails anywhere and together with the mizzen, may have had had some vane affect ?? That boat was also narrow, 11'3" beam and low to the water, so limited windage.

My next boat, a Landfall 43, a staysail rig, not so much. it did have a furling jib, which may have promoted some veering, but the bow was also quite high above water, further causing windage issues while at anchor. Both it and the Roberts were center cockpits. The Landfall was much beamier and in general sat quite high out of the water, much more, so obviously had more windage issues than the R38.

The Beneteau also anchors very placidly, even though it has furling sails up front, but it is aft cockpit and I think having the bimini, dodger, dinghy, etc, back there gives the wind something to push against, like a vane. The Beneteau is also very low to the water.

After many years of experimentation, my anchor setup has always been 150' chain followed by nylon rode.

I have dove on my anchor in numerous wind conditions and have rarely seen more than 20' of chain off the seabed. The weight of the chain plus the springiness of the nylon rode has always given this setup a nice catenary setup and the pull on the anchor is almost always horizontal.

I cannot recall a time when I have ever drug anchor with this setup.

Initially, I used all chain, and in heavy wind, the chain appeared to be quite taught, and I have drug anchor several times, suspected that the anchor was simply yanked out, which caused me to consider alternate options.

But, I recognize that every boat will handle being anchored differently and I offer this point of view. I have seen some boats in an anchorage move around so much it would appear they were sailing, and being within a 200' radius of a boat like that was an invitation for a collision.

[MicHughV]

...this conversation can't be complete without anchor selection, which will also affect one's anchoring technique. I am a huge fan of the Bruce anchor and while I have access to other anchors, I use these almost 100% of the time.

[thinwater]

Originally Posted by a64pilot

It’s the sailrite kit, purchased for as much as anything to give us a project so we could learn the machine some, if they had sizes it would be the big one. I don’t remember if there were sizes or not.
It was a good complete kit if memory serves.
I have split backstays, so I put it of course on on backstay and then take the front line at an angle to other side of the boat, it’s my understanding that they work by putting a lateral force on the boat and not like say a vertical stabilizer on an airplane that works by being streamlined.
But I’ve tried rigging it different ways and it just doesn’t seem to do much.
I also have a lot of windage on my boat, most of it aft of course with Solar which I think is very little windgate, but the dinghy and davits have to be some, but as they “hide” behind the cockpit I don’t think it’s as much as you May think when the wind is straight ahead as in anchoring, but of course becomes real significant under sail.

And yes, it’s only in higher winds that yawing actually occurs, likely 20 ish kts or so.
Real high winds and the yawing seems to stop even without the riding sail, but I have thankfully never sat out real hurricane winds at anchor, probably mid 40’s has been the max for me.

Thanks.


Yeah, I did not find single-luff sails like that kit to be very effective. On some boats it is probably enough.


Interesting that some boats yaw more as the wind picks up, and some less. More I get; it has to do with chain lifting off the bottom. Less may be related to the rode staying tight even in the lulls. I have known of a few that leave a riding sail up (Fin Delta) in tropical storms, swearing that zero yawing is more important than the increase in windage. The over-boom version was designed to stay up in huricane conditions (used with sea anchor).


BTW, I did not test on the cat in the avitar. The hard top is a natural riding sail! Tris and monos.

[Delfin]

Originally Posted by a64pilot

For me a riding sail does pretty much nothing at all. What does work though is a spring line attached about 30’ or so in front of the boat to the anchor chain and led back to one of the sheet winches. I use a sheet winch as it’s adjustable that way. If I did it enough so that I had the length figured out the midships cleat would be just as good.
It doesn’t take as much laying into the wind as you would think to completely stop the yawing.
If you look at the way the Pardey’s say to rig a parachute anchor, it’s the same way, and I assume accomplishes the same thing.

That is pretty fascinating, Pilot. What is the max wind you've used this, and do you find that the boat doesn't try to sail upwind when canted to the wind?

[RichMac]

We were trying to anchor in a vicious, swirling wind in Croatia, gusting 65kts. The yacht was sailing up one side, then swinging across and rapidly ‘sailing’ to the opposite side.

The longer the chain, the longer the swing, our boat(and others) were almost beam on with lots of heel. We gave up before something broke!

But I’ve since thought of a possible solution. We have a downwind drogue, about 6ft, 2m diameter. I wonder what would have happened if I fixed it to the anchor chain, a few metres in front of the bow. Would that have helped the violent swinging, and kept the boat more into wind?

[Malahi]

Interesting observation RichMac. I have the same experience with a Beneteau 42 footer in Greece. When squalls come the wind tends suddenly to veer 90 degrees and increase speed dramatically. The result, with a light modern boat, is that the bows blow off and the boat picks up speed as she blows, until brought up short by the anchor chain going tight. The more chain there is out, the longer the sideways movement goes on. The longer the sideways movement, the more speed is picked up by the boat. Result (as it seems to a non-scientist): the tug on the anchor chain at the end of the scope is greater with a longer anchor chain, other things being equal.

This is not to suggest that short rodes are a good thing, only that once enough chain is out for the conditions, putting out more chain may cause more problems. As an example, I have regularly and successfully anchored in squalls in 4-5 metres of water with 30m of chain on a thick clay bottom (Delta or Danforth anchor), whereas others with 40m of chain or more have dragged.

Perhaps this just reflects differences in anchor type/weight, chain size, anchoring technique, plain mud/mud and weed bottom, etc., etc. (one of the reasons why debates about anchors and anchoring go on for ever!!).