What weight NG anchor for a 20ft yacht?

[chriss999]

I am looking to buy a new anchor and am confused by the weight recommendations given by different manufacturers. For background, my boat is a Kingfisher 20 with 40m of chain, and minimal foredeck space. I'm planning towards a trip to Western Scotland so a good anchor is important. It will replace a 14.75lb cast CQR. Budget is an issue (or else I'd just splash out on the Spade or Knox!)

Some examples of recommendations for my size boat:
Rocna recommend 6kg
Spade say 10kg
Manson Supreme say 7kg
Mantus 8kg,
and Knox say 9kg.

(Not NG, but Lewmar suggest 4kg to 6kg for a Delta and Plastimo say 10kg for a Kobra.)

Can anyone advise whether 6kg or 10kg is nearer the mark for my sort of sailing, please?

 

[simonfraser]

Not a troll I hope
I’d look at what the holding surface is, get the biggest suitable anchor that will fit your boat.
My delta is excellent in mud, now waiting for the 1000 other opinions ...

 

[Tranona]

6kg is nearer the mark with 6mm chain.

 

[Neeves]

All the anchors you list are good anchors and for the same weight I don't think you will tell the difference between them.

One reason Manson suggest 7kg and Rocna 6kg - very simple - that's what they make.

However you will notice the difference when you retrieve the different weight for the different models, especially when you retrieve a large, i.e. heavy, anchor full of mud. You will also notice the difference if you store the anchor down below and have to carry it out of the cabin and down a sidedeck (small twitchy yacht). Alloy, (Spade?) has advantages

I'd agree with Tranona, on chain size, as anything bigger than 6mm is simply too heavy. I would not go smaller than 6kg for the anchor.

If cost is an issue then I suspect a Kobra (which get good reviews from people here) is the best value (pity you did not list prices as well as weight ).

I would not rely on carrying one anchor only. I would recommend you buy 2, of different designs - and an obvious second anchor would be a Fortress, because it is light (and a different design). People lose anchors, been there done that (retrieved it later) - you will look (and feel) very silly if you do not have a second anchor, as good as the first, you are in some gorgeous isolated anchorage on the West Coast of Scotland (where replacement anchor might be like hen's teeth) and you lose that new ?????. This has now ruined your budget.

Finally - many of us, including me, use bigger anchors, ours are 15kg (and many here use much, much bigger, like 50kg). Just because a big Rocna, or Spade works does not necessarily mean a 6kg model will work as well (say in a bit of weed. or in hard sand, or thin mud). I think you would benefit from advice from people who use small anchors on small boats in a cross section of seabeds

Jonathan

 

[webcraft]

.
Knox do a 6.5Kg which should be just fine for your boat.

The 6.5Kg Spade is around the same price though if not cheaper

http://www.spade-anchor.co.uk/S40.htm

- W

 

[webcraft]

Finally - many of us, including me, use bigger anchors, ours are 15kg (and many here use much, much bigger, like 50kg). Just because a big Rocna, or Spade works does not necessarily mean a 6kg model will work as well (say in a bit of weed. or in hard sand, or thin mud). I think you would benefit from advice from people who use small anchors on small boats in a cross section of seabeds

Jonathan

I use a 10Kg Spade on a 27ft boat - it's easy to retrieve by hand and has never dragged, with many prolonged periods spent at anchor in F6-7 .

I;ve got a 9Kg Knox to use with our longer, heavier Morgan Giles 30 and am confident it will be more than adequate. I believe a heavier anchor will never make up for bad anchjor design or poor anchoring technique.

- W

 

[Neeves]

Webcraft,

I admire, and commend, your choice of anchors.

But when I suggest having more than one anchor (being capable of being the primary and each being of different design) I was really thinking of those anchors being on one boat. Sadly for those with multiple boats I would also recommend more than one anchor - on each boat though I suppose as you can only use one boat at a time - you could move them to the active boat.


I do appreciate anyone trying to sail and cruise on a budget - but ground tackle is not somewhere I would want to cut corners.

Jonathan

 

[CAPTAIN FANTASTIC]

If you are looking for "value for money" anchor, I would recommend the Kobra 6kg for around £65. There are so many modern good anchors out there; its like bying a car,

 

[chriss999]

Thank you all for the advice and comments.
My confusion is about the variety of anchor weights recommended on the various supplier sites. The two biggest anomalies I see are:

1) Delta recommend 4kg which seems crazily small for my boat, so I will discount that advice!
2) Spade recommend their 10kg anchor for my size boat, which is heavy for a NG anchor. Maybe it is because their 6kg anchor is only 400 square cm, so will set well but not hold as well as their 10kg anchor which is 600 square cm? But at £352 for a 10kg anchor that pretty much rules it out for me, excellent though it is!

I'll probably go with the 6kg Rocna at approx £200. More than the Kobra but probably better and definitely lighter to handle. PLUS either re-use my CQR as a secondary anchor or get a fortress/guardian - good advice from Neeves to have one up my sleeve.

For interest, I'll post some guide prices in a minute.

 

[chriss999]

Some more information as suggested by Neeves, prices from web searches this month not necessarily RRP's.
Rocna 6kg £203 to £225, fluke area 590 cm2
Spade 6kg £221, fluke area 400 cm2
Spade 10kg £352, fluke area 600 cm2
Manson Supreme 7kg £180, fluke area unknown
Mantus 8kg £209, fluke area 680 cm2
Knox 6kg £282, fluke area 440 cm2
Knox 9kg £288, fluke area 590 cm2

Weights are approximate and fluke areas are from what I can glean online

(Delta and Kobra are cheaper but I've not found their fluke areas)

 

[doug748]

I would probably go for the 6 kg Rocna as well.

Force 4 in Plymouth have them for £206, OTOH I might be tempted plump for the 7kg Manson which they advertise at a very attractive £164.95. The advantage of this is that you can handle both before making your choice. Do check they have both in stock before you travel though.

 

[jordanbasset]

If you are looking for "value for money" anchor, I would recommend the Kobra 6kg for around £65. There are so many modern good anchors out there; its like bying a car,

I'll probably go with the 6kg Rocna at approx £200. More than the Kobra but probably better and definitely lighter to handle.

Ignoring whether it is better or not why would a 6 kg Rocna anchor be lighter to handle than a 6kg Kobra (which Plastimo say it suitable for an 8 m boat)
https://www.plastimo.com/en/ancre-kobra-9988.html

 

[webcraft]

Webcraft,

I admire, and commend, your choice of anchors.

But when I suggest having more than one anchor (being capable of being the primary and each being of different design) I was really thinking of those anchors being on one boat. Sadly for those with multiple boats I would also recommend more than one anchor - on each boat though I suppose as you can only use one boat at a time - you could move them to the active boat.


I do appreciate anyone trying to sail and cruise on a budget - but ground tackle is not somewhere I would want to cut corners.

Jonathan

The Vega also has a 15Kg genuine CQR as backup, and so does the Morgan Giles.

- W

 

[webcraft]

2) Spade recommend their 10kg anchor for my size boat, which is heavy for a NG anchor. Maybe it is because their 6kg anchor is only 400 square cm, so will set well but not hold as well as their 10kg anchor which is 600 square cm? But at £352 for a 10kg anchor that pretty much rules it out for me, excellent though it is!

Spade recommend a 15Kg model for the Vega , but before purchasing I spoke to Alain Hylas, the designer of the anchor, and he reckoned the 10Kg would be more than enough. 15 years and over 20,000 miles with dozens if not hundreds of nights on the hook have proved him right.

With that in mind, I would say the 6Kg is more than adequate for your boat.

- W

 

[johnalison]

I suspect that they would all work perfectly well. We used to use a 15lb Danforth on our 22'er an I think on our 26 as well, in Essex mud, and a 25lb plough on a 29'er, so any of the ones mentioned will be better. 6-7Kg will be easy to handle, 10 becoming noticeable. A friend's wife coped with a 35lb CQR without a winch, so you may as well choose any to suit and then relax.

 

[mbroom]

I would not like to return home to her on a Friday evening with a broken pay packet....

 

[Glenlivet]

Thank you all for the advice and comments.
My confusion is about the variety of anchor weights recommended on the various supplier sites. The two biggest anomalies I see are:

1) Delta recommend 4kg which seems crazily small for my boat, so I will discount that advice!
2) Spade recommend their 10kg anchor for my size boat, which is heavy for a NG anchor. Maybe it is because their 6kg anchor is only 400 square cm, so will set well but not hold as well as their 10kg anchor which is 600 square cm? But at £352 for a 10kg anchor that pretty much rules it out for me, excellent though it is!

I'll probably go with the 6kg Rocna at approx £200. More than the Kobra but probably better and definitely lighter to handle. PLUS either re-use my CQR as a secondary anchor or get a fortress/guardian - good advice from Neeves to have one up my sleeve.

For interest, I'll post some guide prices in a minute.

Why not save some money and stick with the CQR? I had one as the main anchor on my Dufour 29 when I kept it in Ardrossan and did plenty of anchoring, it always set and didn’t drag.

 

[thinwater]

Chriss, was the CQR dragging?

I've had two multihulls (more windage) with 6kg anchors and been quite happy. The reality is that a 20-foot boat with enough rode and a snubber is looking at 60 knot storm loads of about 250 pounds (extrapolated from ABYC table 1). I've tested 2-pound anchors to that in good bottoms. On anything better than smooth rock, the smaller sizes should be fine. On the other hand, a 6kg CQR on its side might well drag.

 

[kalanka]

I think that a further consideration is that the West Coast of Scotland has many anchorages with lots of kelp.

I have a 34 foot sloop and have extensively used both a 45lb CQR and a 20kg Rocna, both with complete satisfaction. Each anchor is overspecified in weight relative to the boat size but in ten years of frequent anchoring I have never dragged on kelp or any other surface.

I believe the extra weight gives extra capability for penetrating the weed so would always err on the side of somewhat bigger than strictly necessary - subject to the anchor not becoming unduly difficult to handle.

 

[chriss999]

Chriss, was the CQR dragging?

I've had two multihulls (more windage) with 6kg anchors and been quite happy. The reality is that a 20-foot boat with enough rode and a snubber is looking at 60 knot storm loads of about 250 pounds (extrapolated from ABYC table 1). I've tested 2-pound anchors to that in good bottoms. On anything better than smooth rock, the smaller sizes should be fine. On the other hand, a 6kg CQR on its side might well drag.

A good question, and I appreciate Glenlivet's thoughts on this too. My anchoring is not really tested except on local cruises in good weather, and I experienced no problem - but I wouldn't expect to given the conditions. As the Scotland trip is a big thing for me I'm happy to invest in the right anchor to reduce the risks, and to reduce the risk of sleepless nights next summer.