Mantus vs Rocna

[Nina Lucia]

All those You tube videos..., is there really right answer or all depends of situation, ground, weather, length of ground tackle...

 

[GHA]

All those You tube videos..., is there really right answer or all depends of situation, ground, weather, length of ground tackle...

Yes.


Doubt very much anyone blindfolded could tell the difference between the new gens in use.

 

[pvb]

Oh, marvellous! I love an anchor thread.

 

[noelex]

Either anchor is a great choice, but in my view the Mantus has better performance, especially in very challenging substrates.

Be aware that while they look similar in photos, the Mantus fluke is both longer and wider than the equivalent Rocna so check if it fits your bow roller before purchasing.

 

[zoidberg]

"Oh, no, it doesn't....."

 

[Sybarite]

Just call a Spade a Spade.

 

[NormanS]

Wait till I check to see which is the more fashionable this week.

 

[LadyInBed]

Delta is a damn sight cheaper.

 

[Orion Jim]

Delta is a damn sight cheaper.

Yes, and there is a reason :ambivalence:

 

[Resolution]

And the Ultra is even better. Specially with the chrome finish. Unfortunately Santa forgot to bring one this year (again).

 

[geem]

I watched a guy for an hour this afternoon trying to anchor his boat. The holding is good, the conditions were fine but his technique was to let about twice the depth of water then see if he could get it to set.......... eventually i went over as he was close to me. Do you know how hard it is to give somebody advise about setting their anchor? However you do it is sounds like you are having a go. I persuaded him to let out at least three to four times the depth before he put any load on it. He said eventually he would have five times the depth! I asked him what he was waiting for? He said he needed to get it to dig in first.........OMG expensive yacht but no idea how to set an anchor.

 

[vyv_cox]

Delta is a damn sight cheaper.

I replaced my Delta with a Rocna after it dragged repeatedly in a soft bottom and a lot of wind. I had used it for 20 years prior to that without a problem.
There are suggestions on Morgans Cloud that the Rocna can give problems resetting due to the extension of the hoop below the fluke. I have not seen this and have photos of mine showing successful resets. However, the Mantus avoids this potential problem.

 

[jordanbasset]

I replaced a Delta with a much cheaper Kobra 2, no problems dragging. I know there are some suggestions about the quality of the shank, but in both of the ones I have owned it has never been a problem

 

[vyv_cox]

I replaced a Delta with a much cheaper Kobra 2, no problems dragging. I know there are some suggestions about the quality of the shank, but in both of the ones I have owned it has never been a problem

I have photos of a bent Kobra shank. But then I also have photos of bent shanks on Rocna, Delta, CQR, Fortress and others. Anything ductile will bend if you apply enough load. The trick is designing that load to be high enough for it to be nearly impossible.

 

[Sybarite]

I have photos of a bent Kobra shank. But then I also have photos of bent shanks on Rocna, Delta, CQR, Fortress and others. Anything ductile will bend if you apply enough load. The trick is designing that load to be high enough for it to be nearly impossible.

Or, if the anchor will swivel quickly in response to change in pull direction, there would be no need for the shank to bend.

In the French tests the Delta and the Kobra have reasonable results but their straight line breakout load is only about half that of the better NG anchors.

 

[Kelpie]

I replaced my Delta with a Rocna after it dragged repeatedly in a soft bottom and a lot of wind. I had used it for 20 years prior to that without a problem.
There are suggestions on Morgans Cloud that the Rocna can give problems resetting due to the extension of the hoop below the fluke. I have not seen this and have photos of mine showing successful resets. However, the Mantus avoids this potential problem.

My understanding of the potential Rocna re-setting problem was that in the right consistency of seabed, you could get a sticky lump of clay/mud adhering to the fluke, and this would alter the balance such that the tip is raised and will not dig in. The conclusion was that a ballasted tip anchor such as a Spade would be less susceptible to this failure mode.

It's a pretty unlikely set of circumstances, bordering on the theoretical, and requires a rapid 180 degree wind shift, so I still sleep quite soundly on my Rocna...

 

[Neeves]

I replaced my Delta with a Rocna after it dragged repeatedly in a soft bottom and a lot of wind. I had used it for 20 years prior to that without a problem.
There are suggestions on Morgans Cloud that the Rocna can give problems resetting due to the extension of the hoop below the fluke. I have not seen this and have photos of mine showing successful resets. However, the Mantus avoids this potential problem.

I believe MorganCloud recommendations were based on some yachts ending up on beaches with their convex, roll barred anchors clogged. I don't think this was restricted to Rocna. Not do I think other NG anchors do not drag.

Jonathan

 

[Neeves]

Returning to the OP's question

A few years ago forum, this one included, was full of threads extolling the holding capacity of the new generation of anchors.

The magazines contributed to this and conducted tests, or published tests from other magazines. or attended tests sponsored by anchor makers or chandlers (the most famous being the tests published by many magazines in 2006 which I think were sponsored by West Marine). These recent tests (and Voile at Voileurs have been very active) have led to the concept that 'in general' the newer designs are better, maybe by a factor of 2, than the old gen anchors. These results have been underlined by Classification Society, or their equivalent, tests confirming that Rocna, Supreme, Fortress, Excel, Ultra and Spade (there may be others) have twice the hold of old gen anchors - of the same weight, or size (in seabeds chosen by the anchor makers - but despite this bias - the result accords with the independent magazine tests).

These tests and the forum threads appear to confirm, and the confirmation is underlined by the numbers of these NG anchors on bow rollers, that the leisure marine public is 'swinging' in favour of these newer designs.

I read a recent BoatUS news release within the last week who clearly stated that the primary measure of an anchor's performance was 'holding capacity', though other characteristic (like does it fit on your bow roller, can you buy it easily etc etc) are also important considerations. I confess to finding it difficult to argue against BoatUS - holding capacity is a critical piece of information.

edit:

This is what Boat US say

"Anchors are rated by "holding power"--which is the ability of an anchor to hold a given weight. Keep in mind that a 10,000 pound boat may only require an anchor with a holding power of a few hundred pounds on a calm day, but may need 1,000 pounds of holding power or more on a stormy day. "

close edit


In answer to the OP - look and find independent testing of Mantus in comparison with other anchors - and make you own decision. The anchor has been on the market for a number of years - check the independent results. Don't be beguiled by pretty pictures and marketing hype - find some independent data where someone has tested Mantus against other anchors - to the limit and produced quantitative information.

But to the OP - no anchor is perfect

But looking at independent holding capacity testing is a good start

And when you find that independent testing and you make your decision some links would be very useful.

Jonathan

 

[NormanS]

Jonathan, you say that so-called NG anchors have double the holding capacity of older anchors. Compared not just by weight, but by size. Specifically, I replaced a 20kg genuine Danforth with a FX23 Fortress, which is about one third of the weight, but is of practically identical dimensions and design. Should I expect twice the holding capacity, and if so, why?

For the avoidance of doubt, the change to the Fortress wasn't to achieve any greater holding, but merely for easier handling..

 

[vyv_cox]

My understanding of the potential Rocna re-setting problem was that in the right consistency of seabed, you could get a sticky lump of clay/mud adhering to the fluke, and this would alter the balance such that the tip is raised and will not dig in. The conclusion was that a ballasted tip anchor such as a Spade would be less susceptible to this failure mode.

It's a pretty unlikely set of circumstances, bordering on the theoretical, and requires a rapid 180 degree wind shift, so I still sleep quite soundly on my Rocna...

I have read that one, but also the one I describe above (possibly not on Morgans Cloud). There are similarities between this and the suggested problem with Danforth-type anchors in which a dragging chain could slide beneath the end of the stock, tripping the anchor.