Thoughts on riding sails and rigging

Many of us here have boats that are "less than well behaved" at anchor in gusty winds. I know on my boat it's an issue of windage being too far forward, as putting the full aft canvas up helps the issue a bit.

Based on that, let's give some thought to riding sails and how to rig one in an effective location (far enough aft) and with an effective shape. Particularly for those of us without masts.

I have a feeling the answer may come to "it's just not practical", but let's see what we can come up with.

I'm thinking one option for those with davits would be a pair of sails rigged from the outer corners of the transom / rail to the davits to help the stern get pushed back in line when swinging off the wind.

rslifkin said:

Many of us here have boats that are "less than well behaved" at anchor in gusty winds. I know on my boat it's an issue of windage being too far forward, as putting the full aft canvas up helps the issue a bit.

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Left adrift with a breeze and absent other influences such as current, the normal attitude for most boats such as ours will be to ride perpendicular to the wind. It is not like a weather vane that will point-up into the wind. Windage forward or abaft will influence the final angle, but for the most part, the boat wants to be perpendicular to the wind. "Sailing" at anchor is the tension of the boat trying to go perpendicular and eventually having the bow snapped through the wind by the anchor. Rinse/repeat. Heavier boats that sit lower and deeper in the water are slower to 'sail' and gather less momentum.

A riding sail will help, but will not eliminate the problem. Many sailors try them. Most give up saying it's surprisingly hard to rig and not worth the effort.

Peter

My boat naturally rides pointed I'd say about 100* off the wind, so the bow blows off severely. The biggest issue is in gusty winds, where it's not uncommon to sit 70 - 90* off the wind, sailing forward (I've seen better than 1.5 kts) until enough tension comes up on the anchor rode to pull the bow around. Then we tack almost 180* (rather quickly if the wind is strong enough) and go off doing the same thing in the other direction. It can't be great for anchor holding and it certainly freaks out surrounding boats, as in deeper water we can sail back and forth a couple hundred feet fairly quickly rather than just yawing in a smaller area like many do.

It also seems like boats with their windage further aft and their drag in the water further forward tend to yaw much less, as they act more like a weather vane. I don't expect it's possible (within reasonable effort) to achieve that on any of our boats, but reducing the angle of yaw should at least tame the behavior some.

On my boat, if I've got all of the canvas up (adds a bit of windage aft) and the wind isn't too gusty and the wind direction is steady, we yaw around a bit, but don't sail. Once it gets gusty or I drop the back canvas during the day, then we start sailing significantly.

Some folks with sailing dinks simply stick the dinkmast aft , and flatted the sail with a down haul.

Part of understanding a boat "falling off " at the bow is the lack of hull or more properly keel at the bow in the water. It's common to see Chesapeake bay waterman's boats where keel has been added all the way to the bow. Visualize traveling up wind to a crab pot. As you slow down, the bow falls off from the wind pushing it. While the added keel doesn't prevent the bow from falling off with the wind, it dramatically slows down the rate of fall off.

My boat "hunts" terribly at anchor. I've found that having a drag weight off the bow with almost zero scope slows the rate of fall off and allows the stern to catch up and the bow to change direction. While the hunting isn't eliminated, it is greatly reduced. Currently I'm using 30 pounds of scuba diving weights. Would like to try a mushroom anchor of about that size.

Ted

I've also considered adding drag up forward (either dragging an anchor or a drogue from the bow). My forefoot isn't cut away like a Sea Ray, but I've got less boat in the water than I do further aft.

Thinking back on hundreds of nights at anchor and at mooring fields, up and down both coasts of the USA, I cannot recall ever seeing a power boat deploy a riding sail. And only on a very few occasions, a sailboat using something like a tightly reefed main. I'm kind of an avid observer of these sort of things, so I tend to assume, "there must be a reason for that".

caltexflanc said:

Thinking back on hundreds of nights at anchor and at mooring fields, up and down both coasts of the USA, I cannot recall ever seeing a power boat deploy a riding sail. And only on a very few occasions, a sailboat using something like a tightly reefed main. I'm kind of an avid observer of these sort of things, so I tend to assume, "there must be a reason for that".

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I've very rarely seen anyone use one either. But I'm not sure why. I kinda figure it might just be a matter of them not having a good way to deploy one that's actually effective.

We have a mast, and I added a boom with a hand powered boat trailer winch and small 'bow roller' at the booms end for hauling our beast of a dinghy onto modified Weaver Snap Davits on the swimstep. The boom almost reaches the transom.

Our riding sail is triangular shaped, about 6' long and 3' tall tapering down to 3" near the 'roller'. It goes up really fast, being tied at only three points, does not interfere with anything, and works like a hot damn.

Our main problem isn't the wandering side to side, it's the bounce on the nylon rode. After a somewhat sideways downwind romp the boat will straighten out and stretch the rode, then the tension in the rode will actually pull our boat upwind, where it falls off the wind the other way and gains speed downwind to repeat the process.

I'd guesstimate the riding sail takes 100% of the 'bounce' out of the system and over 50% of the swing. I'm a believer!

Good luck on finding a solution

The nylon rode bounce is definitely a large part of my problem. Shallower water with less nylon out does help a bit. Unfortunately, my most common close-to-home anchorage here is almost 50 feet deep, so I've typically got at least 200 feet of rode out (which means at least 110 feet of nylon).

Try springing the rode. A line led to a midships cleat from the rode that causes the boat to sit at an angle to anchor pull.

bayview said:

Try springing the rode. A line led to a midships cleat from the rode that causes the boat to sit at an angle to anchor pull.

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Doesn't work well, at least not on my boat. If the winds are gusty, unless we're at least 60* off the wind, we'll at some point still get pulled through the wind and end up scuffing the spring line across the hull and bottom paint. Going to an aft cleat might be better, but I haven't tried that.

We sometimes use a stay sail on our trawler. It helps keep our bow into the wind when anchored or drifting. Depends on the conditions.
Bud

We sometimes use a stay sail on our trawler. It helps keep our bow into the wind when anchored or drifting. Depends on the conditions. Our vessel was pretty much rigged except for the halyard which we installed. We bought a used sail from bacon sails for $50.
Bud

Never noticed the problem. Perhaps having a full keel, all chain rode, and no multiple decks has helped.

markpierce said:

Never noticed the problem. Perhaps having a full keel, all chain rode, and no multiple decks has helped.

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It definitely depends on the boat. A boat with a forward pilothouse and a flybridge on top plus a cockpit aft would likely be worse than behaved than mine, assuming similar hull design.

rslifkin said:

It definitely depends on the boat. A boat with a forward pilothouse and a flybridge on top plus a cockpit aft would likely be worse than behaved than mine, assuming similar hull design.

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The worst behavior I've seen are by relatively low profile boats actually. Boat weight, chain and keel are the biggest helps. High windage boats like our old Hatteras are not really affected significantly if they have those three. We were usually one of the, if not the most motionless boat in the anchorage.

Pretty confident its all about center of lateral resistance below the waterline and center of effort above.

Size and weight affects how much effort is needed but not the actual motion (or lack of it).

Our riding sail goes from the aft end of the boom to about 1/2 to the mast, along the cable supporting the boom end from the top of the mast.

Winds shifted one day and came in our bay at about 20 knots (gusting 25) so that's when I quickly tied a small tarp in place...and...presto...bouncy yo-yo swinging problem solved.

I haven’t put any real effort into reducing the sailing on Willy.

Some thoughts;
On many boats the CG being too far fwd Probably will promote the stern to swing.
Perhaps a plumb bow stem and the resultant deep fore foot promotes the stern to swing.
A large and strong eye bolt through the stem at or near the WL would help lowering significantly the pull of the rode. Dosn’t that stabilize a towed dinghy?
An anchor lowered from a stern cleat. ... or two. Or chain?

In my case, the stern stays put and the bow falls off. Center is wind resistance is forward of the drag in the water (which is mostly the aft end of the keel, props, and rudders)

The times we have used our stay sail mostly has been when the current is perpindicular to the wind/waves so it keeps boat from being side to.

A Finsail works wonderfully. A kellet weight just touching the bottom helps some. Sail rite sells a kit if you want to make your own.
Having a single flat blade riding sail works fine to decrease rolling but the hunting as to get well underway before it has an effect. Having a Finsail or similar prevents the hunting from starting which is much more comfortable.

rslifkin said:

Many of us here have boats that are "less than well behaved" at anchor in gusty winds.

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Boats wag on anchor and a mooring. I'm not clear on what a 'well behaved' boat is supposed to do. I'm not even clear there is a problem to be solved here. Look at a flag in the wind, it is doing the exact same thing.

What you're observing is physics and is expected. What your attempting to solve doesn't make any sense.

Shrew said:

Boats wag on anchor and a mooring. I'm not clear on what a 'well behaved' boat is supposed to do. I'm not even clear there is a problem to be solved here. Look at a flag in the wind, it is doing the exact same thing.

What you're observing is physics and is expected. What your attempting to solve doesn't make any sense.

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The violent sailing and snatching tight, plus presenting the side of the boat to wind gusts leads to a dramatic increase in anchor loading compared to a boat that yaws around less and comes closer to just pointing into the wind. They'll all move around some, but doing 180s and sailing back and forth can be a holding problem on top of being uncomfortable.

Shrew said:

Boats wag on anchor and a mooring. I'm not clear on what a 'well behaved' boat is supposed to do. I'm not even clear there is a problem to be solved here. Look at a flag in the wind, it is doing the exact same thing.

What you're observing is physics and is expected. What your attempting to solve doesn't make any sense.

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There are boats that don't move hardly at all. My buddies 46 Grand Banks Europa sits pretty still. We were anchored next to each other in 30+ knot winds for a day. The boat looked like it was sitting on land.

Ted

Read an analysis of this. Believe it was on attainable adventure. Several things at play to my limited understanding. Wind oscillates in direction. Any windage forward - be it rolled sails, posts, hull, dinghy on deck or house catches the wind on its side Most boats (even sailboats) have less in the water forward than aft. So the bow blows off. The stern with more keel, rudder(s) and possibly hull aft in the water even if it blows off does so slower. Boat pivots presenting more asymmetry resulting in more movement. Eventually stern catches up to bow and boat starts to move to original position but the bow leads. Now whole cycle is repeated on the other side.
Standard flat riding sails and dragging something off the bow hastens the ability of the stern to catch up more quickly so degree of side to side motion is reduced. A 3 dimensional riding sail which presents constant loading like a Finsail helps prevent the motion from starting. Trawlers with the pilot house way aft will”sail” much less. Multihulls with about the same in the water fore and aft and on a bridle will sail less (depending upon appendages). Boats have a center of lateral resistance. The more aft that is in the water and the more windage forward of that point the more the propensity to sail at anchor.
My prior boat would hunt. Surprisely only at certain wind speeds. Above and below those speeds it was steady. Never understood why. However, to get a good nights sleep would leave one snubber at the bow over a roller. Then take the other snubber and secure it a bit back from the bow. Now the boat would sit slightly out of parallel to the wind direction at rest. This worked fine up to moderate conditions. In strong winds had both snubbers equal length and at symmetrical placement as having them load symmetrically seems more important.

If having separate port and starboard snubber lines, make one a bit shorter than the other to reduce wandering.

It's not uncommon where I am (Maine) for lobster boats to have a riding sail and I've seen a couple of more traditional powerboats with one. I'm currently rigging one for my boat both to point her into the wind and to dampen the roll a little when underway. Very common on many European fishing vessels.

Those are pretty. Where did you take that snap?