SO36i hunting at anchor

[Quiddle]

I've just spent my first weekend anchoring in a new-to-me 36i. I was close to a weather shore at three locations in 3-9m with 30m of chain out, water was flat, negligible tide and wind at 15 - 18 knts.
In these conditions the boat seems to veer through 90 degrees over ~2 minute period with fairly marked snubbing at each extreme, causing a loud clank as the bow roller shifts along its axle. This occurs with the rudder free to move, locked to one side and locked centrally.
I've not experienced such extreme hunting in a mono-hull before. Is it peculiar to the 36i and is there a way to moderate it?
Andy

[sitara]

This describes exactly what I have also experienced including the bow roller clanking on my 36i. The hunting is a characteristic of deep in keels. I solved (I hope) the bow roller clanking by putting a nylon washer in the gap at the end of the roller to reduce the movement. There is a good description of the causes of hunting at anchor at www.jordanseriesdrogue.com/D_14.htm. Also a lot of other good information.

I read somewhere about using a bridle system where lines were run from the anchor chain to the mid cleats on both sides and then the chain loosened. This was claimed to reduce swinging but I have not tried it. I have also thought about rigging a "tail fin" at the stern by hoisting an old storm sail on one of the back stays and sheeting it through the genoa rollers, again not tried it.

[j]

This is fairly common with most flat bottomed boats. It is some what reduced by using an all chain rode. We connect our rope snubber then let out several metres of chain so that it hangs in a loop below the bow, this reduces it even more but the boat still wanders around... you get used to it.

Something else to consider is an anchor kellet (we haven't tried one)
www.petersmith.net.nz/boat-anchors/kellets.php

...Other applications

This is not to say that kellets are entirely pointless; they serve other purposes.
They can contain and minimize swing radii in light conditions
They can help dampen “sailing” at anchor

Minimizing swinging circle

This is really the sole use for a kellet which makes sense, although it only applies in light to moderate conditions. It will prevent the boat from aimlessly drifting around the anchor in calm conditions, and will minimize the swinging circle in light to moderate winds. The kellet should be positioned down the rode from the boat a distance equal to that of the vertical distance to the seabed (depth plus height to bow-roller). This allows the gravitational potential of the kellet to work to its full potential.

While this technique is inarguably effective, its necessity could be questionable. Swinging circles are unlikely to be of much importance in an empty anchorage where there is room...

May 21, 2013 22:29:59 GMT sitara said:

bow roller clanking on my 36i.

This is annoying! We intend to permanently fix the roller in position to get rid of the articulation.

[hoppy]

My SO 40 hunts around at anchor like crazy in windy conditions. I have found that a riding sail will calm it down a lot. Unfortunately where I have my riding sail mounted it causes it's tack line to rub against my bimi rail and if I don't remove the bimini it will chafe, so I don't bother with the riding sail if I have the swing room.

I ALWAYS use a snubber when I am at anchor. It takes the stress off bow roller and windlass and thus no bow roller clunking. I learnt the hard way in the first season,when after days of anchoring with out a snubber in windy conditions this happened.

[Quiddle]

Thanks - some good tips. I make the anchor off on a cleat to save the windlass but will add a snubber and an angel (kellet). I'll also try a washer to reduce roller movement - I had a go at jamming a length of 4mm line into the gap which had a marginal effect.
Cheers
Andy

[mkremedy]

]My 2007 36i dances around a lot while at anchor or while on it's mooring. I replaced my chain/ rope rode with an all chain rode, this cut down on the dancing while at anchor. I also drilled a hole the anchor roller fitting to prevent the fitting from pivoting. The helps to keep my anchor way from the bow of the boat when I raise and lower the anchor. While at anchor the roller doesn't make any noise. I also use a snubber to take the pressure off of the windlass.
Happy Sailing,
mkremedy