Plastimo Kobra Anchors

I mentioned Rocna to spread the load. Both CQR and Delta did poorly also. Rocna, Spade, Delta, Bruce and CQR were very poor with Supreme a bit better. Mantus and Ultra were less poor and better than Supreme.. Danforth good and Fortress very good. Ignoring the excellence of Fortress the result I found odd was that Ultra was so much better than Spade and Mantus so much better than Supreme which was better than Rocna. Ostensibly similar designs (Spade, Ultra) and (Rocna, Supreme, Mantus) performed very differently - it is wrong to categorise - or - 'ploughs' actually did as badly as 'new gen' concave.

But there is mud and mud - it is equally difficult to categorise :)

Jonathan
 
Neeves said:
the result I found odd was that Ultra was so much better than Spade
Click to expand...

I find it odd too but I met a Turkish man last season who had gone from a Spade to an Ultra and found it much 'better'. This was in the Aegean, so little chance of mud but he raved about the Ultra in all the conditions he was used to. There do seem to be subtle differences between designs that look the same without getting a tape measure out.
 
The little use I have had of an Ultra, I borrowed one from the distributor (I was not going to buy one) I found it exceptional. I did not use it sufficient to say it was better or worse than a Spade (or any of the other 'good' anchors. Here I was simply discouraged by the price. For less many you can get as good. The Ultra might stay more clean (and be easier to clean) but to me that does not justify the price difference.

But why those anchors, ostensibly so similar, perform so differently in mud, of at least one characteristic. I find very odd. Having said that its a bit academic as in mud, just use a Fortress, in other seabeds the good anchors tend to be much of a muchness, a compromise here and one there.

Jonathan

Jonathan
 
A very old thread, but I am sure many are considering the Kobra.

The Kobra has two different types folding mechanism. The Kobra 1 uses a clip system. This is what caused the grief for the OP. In my view this system is not reliable enough for overnight anchoring. However the so called Kobra 2 uses a bolt in place of the clip. This is secure and reliable with a little care.

Plastimo now uses the bolt system on all Kobra anchors over 10kg. Just make an occasional inspection to make sure the bolt is secure (it is a little difficult to inspect, as it sits under the anchor).

This owner did not realise the bolt was missing and as you can see from the puffs of sand his anchor was dragging:


imagejpg2_zps8f17d170.jpg



imagejpg1_zps3cdb01f8.jpg
 
Last edited:
Review of the Kobra 2 anchor in comparison with others
http://www.manson-marine.co.nz/Anchor Tests/Yachting Monthly -Anchor Test Nov09.pdf
'Our underwater footage proves the excellence of the design – the Kobra was the second-best anchor on test – and its behaviour in use was reassuringly predictable. It never failed to set, always digging in rapidly and burying itself well. It’s assuredly the winner of this test. Taking into account the modest price tag, it’s excellent value-for-money. '

Other anchors on the test were CQR, Britany, Spade, Brake, Delta, Manson Supreme, XYZ, Fortress, Bugel
 
Last edited:
I have used many anchors over the years; I now have a Kobra 2; it sets straight away and holds well. I have not used it in rough seas but I have used it in fast tide and deep water without issues.
 
When Rocna made the mistake of stating on their website what material they used for their shanks, which when they subsequently bent proved to be untrue, the resulting furore sent the company into administration. The low cost of the Kobra suggests that their shank is made from similar stuff to that of the bendy Rocnas but of course, not having stated that they used high strength steel, nobody is the wiser. I have not seen a bent Kobra but when I do it will come as no surprise.
 
I saw my first bent one in Preston Marina, or the marina at Preston (yes in the UK). It was only slightly bent but a bit of a worry as I bought our Kobra from the chandler there (at the same time).

As Rocna demonstrated - if you make an anchor that holds well then it needs a robust shank. Odd the lesson never got through.

http://www.ybw.com/forums/showthread.php?432850-Oops&highlight=Oops

Jonathan
 
Here is a picture of a bent spade anchor
http://www.ybw.com/forums/showthread.php?323984-Bent-anchor!

Here is a link to a bent Rocna
http://www.cruisersforum.com/forums/f118/rocna-anchor-fail-59164.html

In reality most if not all anchors will bend if the right pressure is applied at the right place. We had our Kobra 2 for 4 years and more than once caught it in rocks and probably used far too much pressure to try and get it out. Fortunately it never bent in all that time, but that is not to say it would not, just that it didn't,
 
Last edited:
jordanbasset said:
In reality most if not all anchors will bend if the right pressure is applied at the right place.
Click to expand...

Of course, and I make exactly that point in my anchors talk, with photos. I am simply pointing out that you largely get what you pay for. Strong shanks, whether tubular or triangular section, heat treated steel or other strengthening methods, cost money to manufacture, as do the other complex methods used by several makers.
 
I agree fully with Vyv. You are very naive to think spending for a similar weight of anchor stg100 or stg300 you are getting the same quality of product. Most of the better anchors have reviews and have been tested and it is easy to differentiate the top 5 or 8 (whatever). These reviews are limited to how they set, what their hold is - very few reviews look at structure and strength. I do not think you will, in general, be able to tell any difference in performance. Price is a very good indication of the care, including choice of steel quality, with which they are made.

You can bend the shank of any anchor - though you are very hard pushed to bend the shank of an anchor composed of 800 MPa steel, like the Supreme, Knox and Excel, as you are as likely, more likely, to bend your bow roller. It is quite possible to straighten, quite easily, a mild steel shank - you would not be able to straighten a HT steel shank (or not with any device available to most of us).

Manson, Anchor Right, Fortress, Knox are all made in high cost locations (and have HT steel shanks, Supreme, Excel, Knox), Spade is a very complicated design to make, Plastimo, CMP, Mantus have the advantage of cheap labour (and cheap steel and if you use a low quality steel, cheaper still). Whether we always enjoy the cheap production base is debatable. But if its really cheap - savings have been made somewhere (the marine industry is not altruistic).

Jonathan
 
Some of us believed all that, until we found that one of the more modern types, for which it was claimed that it was made of a high spec steel, and hence its high price, turned out to being made cheaply out of fairly ordinary steel. That didn't do its reputation much good.
 
It does not appear to have done its reputation any harm at all - many members here mention they buy one (but maybe they do not know the history). If anything the furore put its name on the map - there is no such thing as bad advertsing.

Hopefully it was an exceptional (and sordid) case. I would have liked to have thought that the evidence, that shanks can bend very easily if made from 'a' mild steel, might result in better anchors and more scrupulous attention to detail. There have been at least 2 anchors introduced since that suggests my 'thoughts' are romantic nonsense.

Jonathan
 
Neeves said:
It does not appear to have done its reputation any harm at all - many members here mention they buy one (but maybe they do not know the history). If anything the furore put its name on the map - there is no such thing as bad advertsing.

Hopefully it was an exceptional (and sordid) case. I would have liked to have thought that the evidence, that shanks can bend very easily if made from 'a' mild steel, might result in better anchors and more scrupulous attention to detail. There have been at least 2 anchors introduced since that suggests my 'thoughts' are romantic nonsense.

Jonathan
Click to expand...

In French reviews the Kobra2 was considered a good value for money anchor but which could possibly unhook in the event of a direction shift. In comparative tests (iirc) in a straight pull on sand they broke out with a traction of a little over a tonne.

The Fob Roc held to well over two tonnes and the report indicated that the Rocna was up to the Fob Roc standard.... And similar in price. The Spade held best at about 2 1/2 tonnes. The figures are approximative from memory but the comparison holds good.

No interest in any but very tempted to get a Spade for any new boat I might get. Its cost in relation to the boat's cost is peanuts and helps you to sleep better at night.
 
Sybarite said:
In French reviews the Kobra2 was considered a good value for money anchor but which could possibly unhook in the event of a direction shift. In comparative tests (iirc) in a straight pull on sand they broke out with a traction of a little over a tonne.
.
Click to expand...

I assume you mean the test referred to here

http://baatplassen.no/i/topic/61889-cqr-anker-ble-slaktet-i-ny-test/
'11 anchors tested on sea bottoms of sand and sand + mud:
Winner of the steel category is Spade, with an average holding in hard sand of 1905 kg and on sand + mud of 570 kg (value recorded before rupture of the fixation of the dynamometer).

The second is the Kobra 2 anchor from Plastimo with an average holding in hard sand of 1263 kg and on sand + mud of 1058 kg - the Kobra anchor represents the best compromise characteristic /price.

In third position comes the Bügel anchor with an average holding in hard sand of 1138 kg kg and on sand + mud of 999 kg

The fourth anchor of this comparative test is the Supreme with an average holding in hard sand of 1076 kg and on sand + mud of 631 kg. In spite of honourable results, this test confirms that the “Roll bar” anchors are not, and by far, the best .

In fifth position comes Brake, followed in sixth position by the Delta with an average holding in hard sand of 450 kg and on sand + mud of 662 kg. If these characteristics are sufficient to ensure the holding of a boat in more than 95% of the cases, the perfomances of the Delta are disapointing and far behind the best in the test

Come then Britany with passable results and the two last from the test with frankly bad results: anchor XYZ and the last, the CQR with an average holding in hard sand of 206 kg and on sand + mud of 363 kg

The conclusions of this test are:

- the aluminum anchors give as good performances as the steel models, with however the disadvantage of being more fragile.

- New technologies of anchor are definitely more powerful than their glorious elder, with double, to see triple values of holding.

- Spade, Kobra 2, Bügel and Manson Supreme are excellent anchors having significant differences compared to the traditional anchors'

The person posting does make the qualification that The bigest shortcoming of this test is that it is published in French. I do not plan to translate it totality , but for those which do not perfectly practise this language, I will try to report the general outlines: '
But from my memory of the test his translation does reflect what Voiles & Voiliers published in the 2009 article.
Yes the shaft of the Kbora 2 is probably not going to be as strong as the spade, but in real world conditions for most people that use them it appears strong enough. Also at a quarter of the price of the spade it is a good compromise. I have just bought a new boat (to me) and it has a delta on it, I will replace it with a Kobra 2 if I can source one locally in Greece.
 
Last edited:
jordanbasset said:
The person posting does make the qualification that The bigest shortcoming of this test is that it is published in French. I do not plan to translate it totality , but for those which do not perfectly practise this language, I will try to report the general outlines: '
Click to expand...



I think it was the 2009 test conducted by Voiles et Voiliers that is referred to.

You can read an English write up of this test here:

http://www.manson-marine.co.nz/Anchor Tests/Yachting Monthly -Anchor Test Nov09.pdf

The same magazine did another test in 2012 and the Kobra only scored 2 stars. The best anchors Rocna, Spade and FOB rock received 4 stars. I don't have a link to an English translation of this, but these were the results in French.
 

Attachments

  • image.jpg
    image.jpg
    68.3 KB · Views: 4
Thanks Jordan,

I would have to say that the Kobra is more 'fragile', I prefer the word 'weak'. than any of the mainstream alloys, Fortress, Excel and Spade. I would also agree you cannot differentiate between an alloy and steel Spade nor a alloy and steel Excel - of the same physical size. We have retired our 15kg steel Excel, at least temporarily (its now sitting in our workshop ,along with our steel Spade) and we are only carrying an alloy Excel, on the bow roller, an alloy Spade and a FX 23 (each of which weighs 8kg). We have no doubts of our choice - if we are embarrassed, I'll say so :).

The reasoning is that we have now gone to 6mm HT chain, for a 7t, 38' cat. I neither believe in 'catenary' nor that you need an oversize anchor - and I'm putting my money in my beliefs.

What I find really annoying of the Kobra - it could have been a real contender if only they had used a better steel in the shank.

Jonathan
 
Last edited:
I have to agree with Sybarite, anchors cost nothing compared to the value of a yacht and if you value a relaxed sleep a good anchor is worth every penny you spend.

But if there was a finite kitty and the choice was a correctly sized Kobra or a grossly undersized, Supreme, Excel, Fortress, Spade etc (all for the same money as the Kobra) I'd go for the Kobra. But I am fully aware of the Kobra's Achilles heel and could therefore be 'careful'. Judging performance of anchors is subjective at the best of times trying to equate parsimony with performance is even more difficult. Consequently - I think it good value for money, at least it 'performs' which is more than can be said for many cheap anchors.

Jonathan
 
It is a speculation that the Kobra has weak shank. However, I would prefer a shank that bends than a shanks that snaps due to strong but brittle material. Ductility in mild steel produces a very forgiving material; it's a compromise.
 
You must log in or register to reply here.

Share this page

Top