Sailing behind anchor Vision 42

[Ronald]

Hi when we are at anchor we find ourselves swinging around a lot especially when the wind increases to above 10 knts.

Looking at the issues at the Internet there are suggestions of putting a sail at the rear of the boom.
It appears some kind of triangle shape is recommended

I found this on line are there any Vision owner using this and the most important question off course does it work.
https://www.bannerbaymarine.com/index.php?l=product_detail&p=25

Ronald.

[Rampage]

Riding sails work well in calming down the amount of swing at anchor in a blow but they’re a bit of a pain to rig and de-rig.
We’ve found that using a reasonably long two legged bridle (the bridle legs are each 5 metres long) from the fore cleats to the anchor chain works well.  It doesn’t stop the swinging but it does reduce it and, most importantly, stops the violent change of direction as you come to the end of the swing.  If you watch the bridle working in a blow, as the boat swings, all the strain is taken on one leg which stretches, absorbing energy.  As the boat comes to the end of the swing, the load goes off both legs before the boat starts to swing in the opposite direction.  With no bridle, the chain would go slightly slack and as tension comes onto it again, that’s what generates the snatch load.  The bridle also stops the chain rumbling on the roller, as the strain is taken by the bridle through the fairleads.

[Ronald]

We do use a rope to take the load of the chain, to make that in to a bridle is not to difficult to do.

I will set this up.

But as you mentioned it does not take the swinging out, it slows it down, 

So my question on the sail remains, and I hope someone is willing to share his experiences, good or bad.

Ronald.

[Craig]

Why not drop your second anchor on a short rode ( about 1.5 times depth) over the bow. Will stop most of the swinging and reduce the extra forces ( about double the usual load) when boat swings back.

Craig
"Shirley Valentine"
Gold Coast
Australia

[SofiaB]

I have a Vision 46 and swing a lot. In 25 knots of wind it swing violently and if I don’t lock the wheel the wheel turns rapidly like reversing without holding it. I’m worried about damage to the steering system!  I suspect the high freeboard and width carries all the way back is the cause. I’ve thought about this sail also and may invest.

[Yngmar]

Sailing at anchor comes from having more windage forward and not enough aft, so the bow breaks out and gets blown off until stopped by the chain (which also causes the chain to sweep along the seafloor in a wide arc, abrading the galvanizing, especially on sand).

You can change this balance though. It's hard to reduce windage forward (unless you didn't furl your headsail well or something), but not difficult to add more aft. We tried a riding sail a few times and that helps a good deal, but it's a bit of faff to set up on our boat. We also have a zip-on attachment that goes aft of the bimini and then down to provide shade from the rear. Turns out that thing works even better, as it catches a lot of wind at the back of the boat and vastly reduces the sailing at anchor

Of course everyone already uses a snubber to take the load off their windlass and absorb snatching. We did try a two-legged snubber (bridle) briefly, but found it made no difference to the swinging on our boat except in very strong winds (45+ kts). And that's when we take the Bimini down!

Locking the helm helps too, as the rudder provides more resistance to the sideways movement - and prevents wear on the steering.

[MagicalArmchair]

45+ kts at anchor . What anchor set up to you use?

[Yngmar]

45+ kts at anchor . What anchor set up to you use?

A Rocna 25 kg (the 33kg didn't fit on our bow), 75m of Grade 70 (high tensile steel) 8mm chain, and in strong winds an extended snubber from both bow cleats. In light winds only a shorter single one. This setup has held the boat in gusts over 60 knots on a few occasions.

Key is to set the anchor well and give it enough scope to work. When expecting some wind, we usually start with 5:1 and go up to 7:1 if there's room. Then you reverse on it with the engine, hard and for a good 10s or so (less hard if it's already blowing a lot, as wind pressure and engine power add up). This both sets the anchor and gives you some assurance that it will hold if the wind continues to blow from the same direction.

Also anchoring in the right bottom helps! The other thing is to avoid being near other boats, as they're the biggest danger due to poor anchoring skills and ending up dragging onto you. We haven't dragged in a while, although it can happen of course if you end up in a lousy bottom or with a pair of trousers impaled on the tip of the anchor

Diving your anchor is a great exercise and learning experience. You get to see how it has set (or if not), how far it took to do so, how deep it is and what sort of bottom it is. Often the bottom is not what people expect when they look at it from the bow, for example what looked like a sand bottom might be a thin layer on top of plate rock. If you're a good swimmer you can dive on your anchor in a storm (use fins) and see with your own eyes how little catenary there is and what sort of angle the chain is pulling on the anchor with

45+ knots is nothing unusual in the Aegean, we've spent days sitting in that in Kolpos Lakonikos while waiting for the Meltemi to subside enough to be able to round Cape Maleas and then some more on our way northwards back to the Corinth canal. Also the odd thunderstorm (common in autumn in the Med) will come with gusts of that sort, and we've had a few other places where katabatic winds hammered us at night (Sesimbra and Mullion Cove come to mind).

[GVB]

We have Vision42 2013. The high sides catch the wind no doubt and the swings a lot. I’ve found that setting up a small bridle from cleat to cleat the foredeck and then running the snubber line thru the anchor channel helps.. The problem also is that the Vision42 has no fair leads.

[Craig]

Got caught in the Bora in Croatia in March 2010. Winds over 35kn for 3 days, final day 50kn gusting up to 75kns. Didn't know the marinas stopped allowing boats to enter once winds got above 30kns.

Anchored in Pula in a good muddy bottom in about 4 m of water. ( not far from the colosseum). No wave action.

Initially had about 50 m of 8 mm chain on a 23kg Kobra anchor and this held my Bavaria 38 Ok in winds up to 50kns. but the "sailing" on the anchor would roll you over in the bunk when the boat "tacked" back. By putting the second anchor ( the CQR that came with the boat) on a 15m to 20m chain rode greatly reducing the "sailing" back and forward and reducing the increased load when the boat "tacked" around. This second anchor would occasionally drag and as it wasn't on the windless, the main anchor was let out a few metres to adjust the tensions. Eventually had about 60-70 m of main chain out.

Catenary is a myth once winds get much over 25kns. In 60kn winds, the chain didn't touch the water for a few boat lengths. Heavy chain is useless in strong winds. If you want to put more weight on your boat, invest in a bigger anchor.

With this set up there was no jerking on the chain and no shock loadings. No need for snubbers, however we did rig lines from the chain to take the force off the windless. The lines were led back to the bow cleats, then additional lines from the bow cleats back to the main winches to take the load off the cleats.

I've seen figures ( can't find at moment) that measured the difference in loading on the anchor. Basically, when the boat tacks, the loading on the anchor doubles. It is not a "shock" loading like you may get from a falling object. The second anchor deployed would not have held much force but it stopping the "sailing", thus removing the doubling of the load.

Another boat nearby laid out 2 anchors in a "V" pattern to divide the load. This did not work. It was easy to see how the load was merely transferred from one anchor to the other as the boat "sailed"  and dragged both anchors together. Luckily this happened in 40kn winds, not the 60kn + winds and they were able to pull up the anchors, untangle and reset.

Judging by the mud on the chain, diving on my anchors would have been useless as they would have been completely buried.

Craig
" Shirley Valentine"
Gold Coast
Australia