Manson Supreme in Weed

[Teeto]

After cruising 6,500 miles with total success anchoring with our Manson Supreme, we now find ourselves in weedy territory. The locals seem to use either the Admiralty or Stockless. Do we need to buy a new anchor? Would appreciate opinions from sailors on whether the MS is reliable in heavy seagrass.

[donradcliffe]

Depends on the size of the Manson--75 pounds and up will dig right through the grass roots.

[Teeto]

Ours is 60lbs so I guess might not get through. I suppose if we try a few spots and are happy to reanchor if it doesn't set......I assume once we get it set, it will then hold?

[donradcliffe]

That is why you back down on it.

Not all weedy bottoms are the same, and there is no way to guarantee ahead of time whether any anchor will hold. A lot of my weedy bottom experience is in the Med, and sometimes I had to dive down and work the anchor (60 lb bugel) through the roots, but once through the roots the mud was pretty firm. The sharp point worked a whole lot better than my Bruce or others CQRs. Diving on a lot of anchors, I saw that heavy anchors of any type penetrated better.

This summer I took a GB42 with a 60 lb Manson up the east coast and into the great lakes. The only time I had a problem was in a combination of heavy weed and soft mud in the 1000 Islands area of the St Lawrence. When I brought up the anchor, it had about 200 pounds of mud and weed on it, but it was choked with weed to the point where it slowly slid backwards in 30 knots. OTOH, I probably anchored in the weeds 50 times with no problems.

Another thought in weed--if the anchor does not set almost immediately, you had better bring it up and clean it off.

[noelex 77]

Performance in weed is probably one of the most difficult aspects to assess. When I dive on anchors in thick weedy locations the anchors are very hard to find. When you do find them, even when you dive down, its hard to judge how well they are buried in the substrate rather than just hidden by weed.

When backing down even at full throttle we don't put much force on the anchor and thick weed will often hold full reverse just on the weed alone. This will fail when the wind picks up.

There is also a "scale effect". Anchor manufacturers would like you to believe large and small anchors of the same design on appropriately sized boats will perform identically. With weed this is not the case. The weed roots do not change size. A large heavy anchor on a large boat will cut through weed that a smaller lighter anchor of the same design on the smaller boat will not penetrate.

Finally the weed tends to be inconsistent both in a single anchorage and between different areas.

So be careful with reports on weed performance of anchors.

For what it's worth I think the best anchor in weed is the fisherman and its various derivatives. The second best is the Manson Supreme / Rocna. Others would rate the Spade as best or second best, personally I think the Spade is only fair in weed, but this illustrates the difficulty getting good consistent data on weed performance.

At best thick weed is bit of lottery. Set an anchor alarm and be suspicious of the set, particularly in winds above 30k which is where an anchor holding just in weed, rather than set properly in the substrate will let go.

I don't carry a fisherman anchor, the limitations of this anchor means it does not quite justify its superior performance in weed in my circumstances. Try your MS and report back. We like a good anchor thread on CF

[Teeto]

Thankyou Noelex 77. Great answer and we shall report after numerous investigations.

[SV Demeter]

Weve been using a 60lb manson here in St. Martin in the lagoon and are in weeds. I had to set it a second time when first anchoring but after 5 days it seesm to be doing fine. Weeds here are think but not what I would call insanely think weeds. I think Noelex 77's analysis is spot on. FWIW this is the first anchorage I have had to pull up and reset the Manson. Every other time it has set on the first try, but we have only been crusing the eastern caribbean since November.

[motion30]

In my experience a danford is better in the weeds, the sharp fluked dig in when my manson would not

[colemj]

Danforth style anchors do cut through the weed well, but if the wind shifts, they will never reset again. I would not be comfortable on one unless I felt sure the boat was not going to change direction.

Extremely heavy weed was the only time our Rocna has ever failed us, and it took 40kts to pull it out. It came up with a 100lb weed ball on it. We backed down hard with both engines when setting it, but I don't think you ever get a true ground set in heavy weeds - it is just too far to the rootless bottom.

I think the roll bar on the Rocna/Supreme/Bugel hinders penetration in weed. Possibly the Spade would be better, but it has a thicker body profile that could also hinder it.

Weed bottoms suck.

Mark

[klem]

For pure setting ability in weeds, my opinion is that a fisherman anchor is best. However, once set these anchors have a couple of problems. First, they have very low holding power for their weight so they need to be massive. Also, they veer and reset very well if there is a lot of tension on the rode but if it is light conditions, the chain can wrap around the exposed fluke making the anchor pull free without resetting.

In my experience and watching others, the manson supreme sets better than any other anchor in weeds but it is not perfect. Since it has much better holding power than a fisherman (still not great) and doesn't risk fouling on the chain as much, it would be my first choice for anchor type in these conditions. These are very hard conditions and your safety factor will be much lower than in most other conditions.

Noelex 77's post provides good advice.

[Teeto]

Thanks Klem, water visibility seems quite good down here in South Australia. We shall try to aim for the sandier patches where we can. I hear that sometimes the bottom is weed over shallow sand on a limestone substrate.
Anchor alarm will be obligatory I think.

[JonJo]

From trying to anchor in Tasmanian weed, with an Excel, our experience is - try not too. But ours is only 16kg. It will cope with light weed but once the weed forms a dense mat - so you can see no sand between the weed fronds, I suspect ours is simply too small.

The only solution we find, as someone has already said, weed is not consistent and in some weeds beds there are large holes that can be completely weed free. In daylight these are easy to see, the sand is white and weed black. Anchor in the sand. I'd still be using an anchor alarm as if you do drag (change of tide, wind) the anchor will not re-set in the surrounding weed. Anchoring at night is more of a nightmare - if you have a good fishfinder it will differentiate weed and sand on the bottom. Our preference is to move on (to an anchorage we know is weed free) or plan not to arrive at night.

[Livia]

The only time we had problems setting our Manson Supreme was on a thick kelp covered bottom. We moved over a bit and found less kelp and set fine. Our old CQR which we no longer have had problems in kelp as well. Seems a trick set for any anchor and I would guess the sharp tip on our Supreme helps.

[Kettlewell]

Haven't tried a Manson yet in weed, but a Bulwagga does work well there--unfortunately, they are no longer being made. The scoop type anchors (Rocna, Spade, Manson, etc.) may have a weak spot in heavy weeds and/or clay type bottoms, where the scoop can fill up with a big ball of bottom stuff and then no longer penetrate. I have seen scoop types come up with a huge ball of weedy mud several times in a weedy place I anchor a lot.

[downunder]

Originally Posted by colemj

Danforth style anchors do cut through the weed well, but if the wind shifts, they will never reset again. I would not be comfortable on one unless I felt sure the boat was not going to change direction.

Extremely heavy weed was the only time our Rocna has ever failed us, and it took 40kts to pull it out. It came up with a 100lb weed ball on it. We backed down hard with both engines when setting it, but I don't think you ever get a true ground set in heavy weeds - it is just too far to the rootless bottom.

I think the roll bar on the Rocna/Supreme/Bugel hinders penetration in weed. Possibly the Spade would be better, but it has a thicker body profile that could also hinder it.

Weed bottoms suck.

Mark

Would be interesting to see how a reasonable sized new manson Boss and SARCA Excel without the Roll Bars perform in weed.