Rocna Mk II

[malbert73]

I wonder though- I believe part of my personal Rocna failures in soft mud were due to the smaller rollbar being less effective in orienting the Rocna tip down- consistent with Panope’s video showing a Rocna stably upside down

My failures were fixed by moving to a Mantus M1 which has been brilliant and flawless, literally, in 100s and 100s of sets between Chesapeake and New England.
Mantus and Viking have much larger/wider rollbars than Rocna or Manson. They are also hence more vulnerable to bending but I’ll take that chance any day for a anchor that doesn’t drag.

I think rollbars are the same as ballast in non-rollbar anchors: “wasted material” that helps them set. You need one or the other- and neither contributes to holding power. but the right rollbar design can be neutral regarding digging in, etc. I can’t see my huge M1 rollbar possibly clogging on anything but an engine block or the like [emoji3]

[Muaddib1116]

Originally Posted by Panope

Earlier in my testing, the best anchors tended to be the non-rollbar types.

However, after expanding the testing into a wider variety of seabed types, two rollbar anchors (Viking and Mantus M1) have emerged as the best "all around" performers.

Here is a story that might be telling:

I was readying my skiff for the task of towing a 30 foot sailboat for a distance of about 25 miles. With no information about the sailboat's anchor gear, I decided to grab, at the last minute, an anchor that could be used in an emergency to keep both boats off the rocks.

At my feet, on the floor of my shop, was my vast pile of anchors in the "20 pound" size range.

Without any prejudice, or other subjective motivations, I looked down and asked myself: "Which of these anchors as the greatest chance of producing a positive outcome?"

I grabbed a 21 pound Viking (an equal size Mantus M1 would have been just as good, but mine only weighs 17 pounds).

Note that I have bent Viking and Mantus M1 anchors during high pull tests.

If..... IF this new Rocna can perform as well as the Viking and M1 anchors, AND be as strong as the original Rocna, they just might have a game changer.

It generally appears to me, from watching your videos, that in terms of setting and burying characteristics, the viking and mantus m1 performance is largely due to the thin, large surface area flukes. It looks like they added a small ballast bulb in an effort to increase tip weight without drastically changing the overall dimensions/geometry of the rocna shape. So they are likely not drastically increasing fluke surface area, while at the same time making it thicker. It will be interesting to see how this performs compared to the Viking and m1.

[DumnMad]

Peter Smith explains his Rocna II evolution from the original Rocna and Vulcan. Makes sense to me.
His own 55kg is understandably heavy for a 15.5m x 25t boat. One size up on the Rocna chart sizing.
25minute vid but you can start around 14minute mark.

https://www.youtube.com/watch?v=xgqIDCteq5I

[IslandHopper]

Some Australian price comparisons for the new Rocna II v the original.

Original 40kg

https://boatersworld.com.au/rocna-or...-4kg-to-110kg/



Rocna II 40kg

https://boatersworld.com.au/rocna-mk...d-4kg-to-50kg/

[Dockhead]

Originally Posted by jordanbigel

I had to look up "furphy" - "A rumour or story, especially one that is untrue or absurd." - a bold claim. And yet you say at the start "Who knows" so, "MAYBE a furphy"?



Meanwhile, I wish I knew if you are right, I am considering switching from a Vulcan to a (larger/heavier) RocnaII because I am of the belief that the rollbar is an improvement to the Vulcan, which (I thought) was a compromise for boats which can't fit a rollbar.

I think actually that the roll bar is to save cost. Ballasting a non rollbar anchor is costly and relatively complex. I haven't used the Vulcan, but other non rollbar anchors Ive used (Spade, Ultra) are much better than the 55kg Rocna I had.

[Panope]

Originally Posted by IslandHopper

Some Australian price comparisons for the new Rocna II v the original.

Original 40kg

https://boatersworld.com.au/rocna-or...-4kg-to-110kg/



Rocna II 40kg

https://boatersworld.com.au/rocna-mk...d-4kg-to-50kg/

Thanks for posting this, IHop.

It appears that Rocna has 'pulled out all the stops' in an effort to make a premium anchor. And priced accordingly.

For the smaller, 20 kg. versions, the price difference is even greater. Almost double for the MK2:

20kg mk1 = $891
20kg MK2 = $1660

In the video, Mr. Smith indicated that the complex shapes of the MK2 shank are machined, rather than cast. That sounds very expensive.

Also, the SOLID cross section rollbar does not look cheap, either.

I think this anchor has a high probability of raising the bar of anchor design.

[rslifkin]

Originally Posted by Dockhead

I think actually that the roll bar is to save cost. Ballasting a non rollbar anchor is costly and relatively complex. I haven't used the Vulcan, but other non rollbar anchors Ive used (Spade, Ultra) are much better than the 55kg Rocna I had.

To some degree, it's a trade off in design. Without needing that ballast, you can get more fluke area for a given anchor weight. But you risk clogging issues and other concerns that come along with the rollbar design.

[malbert73]

Originally Posted by rslifkin

To some degree, it's a trade off in design. Without needing that ballast, you can get more fluke area for a given anchor weight. But you risk clogging issues and other concerns that come along with the rollbar design.

Yes, that. Dead weight in an anchor contributes nothing to holding power.
The Mantus M1 rollbar is pretty light so more weight is in fluke area relative to total. And also contributes nothing to holding power.
Ballast and rollbars are just to promote setting.

[s/v Jedi]

Originally Posted by Panope

Thanks for posting this, IHop.

It appears that Rocna has 'pulled out all the stops' in an effort to make a premium anchor. And priced accordingly.

For the smaller, 20 kg. versions, the price difference is even greater. Almost double for the MK2:

20kg mk1 = $891
20kg MK2 = $1660

In the video, Mr. Smith indicated that the complex shapes of the MK2 shank are machined, rather than cast. That sounds very expensive.

Also, the SOLID cross section rollbar does not look cheap, either.

I think this anchor has a high probability of raising the bar of anchor design.

Steve, do you have a place where we can check the latest revision of your anchor test results table? I have the idea I’m looking at old data….

[Dockhead]

Originally Posted by malbert73

I wonder though- I believe part of my personal Rocna failures in soft mud were due to the smaller rollbar being less effective in orienting the Rocna tip down- consistent with Panope’s video showing a Rocna stably upside down

My failures were fixed by moving to a Mantus M1 which has been brilliant and flawless, literally, in 100s and 100s of sets between Chesapeake and New England.
Mantus and Viking have much larger/wider rollbars than Rocna or Manson. They are also hence more vulnerable to bending but I’ll take that chance any day for a anchor that doesn’t drag.

I think rollbars are the same as ballast in non-rollbar anchors: “wasted material” that helps them set. You need one or the other- and neither contributes to holding power. but the right rollbar design can be neutral regarding digging in, etc. I can’t see my huge M1 rollbar possibly clogging on anything but an engine block or the like [emoji3]

My experience with the Rocna in soft mud is the same as yours. Basically, it doesn't work in that kind of bottom -- forms a ball of mud around the anchor which can't set.


I can't comment on Mantus.


As to ballast, however -- ballast is not just to add weight. It's to add weight IN THE RIGHT PLACE, to balance the anchor towards the tip so that it orients itself automatically. The roll bar is in my opinion a cheap way to flip the anchor mechanically, which is unbalanced because it lacks ballast.



My experience with roll bar anchors is that they are severely unbalanced, which causes different problems, including getting the anchor back into the roller. Again, that's my experience with Rocna. Haven't tried the Mantus.

[Dockhead]

Originally Posted by malbert73

Yes, that. Dead weight in an anchor contributes nothing to holding power.
The Mantus M1 rollbar is pretty light so more weight is in fluke area relative to total. And also contributes nothing to holding power.
Ballast and rollbars are just to promote setting.

Dead weight does help setting, however, which is just as important as holding power. If you can't set it, the holding power is irrelevant.


I don't think it's desirable to have the maximum fluke area as possible for a given weight. Adding weight without adding bulk is usually not such a problem as adding more bulk. Anchor handling is usually limited by bulk, not weight, certainly in my case it is.

[AiniA]

I spent some time with Smith in Luderitz, Namibia years ago. We were the only two boats there. I had a Manson Supreme anchor, he was not impressed since he thought (correctly) that the Supreme was basically a Rocna knock-off.

[Panope]

Originally Posted by s/v Jedi

Steve, do you have a place where we can check the latest revision of your anchor test results table? I have the idea I’m looking at old data….

For latest data, look for recent 20lb/10kg (range) anchor test videos (I consider the 45lb/20kg data to be superseded by the smaller anchor data).


Note: If we disregard the "Cobblestone" seabed (none of these anchors function here), and arbitrarily set the minimum acceptable holding at the "20" holding factor line, we find that only two anchors pass muster - The Mantus M1 and the Viking.

[malbert73]

Originally Posted by Dockhead

Dead weight does help setting, however, which is just as important as holding power. If you can't set it, the holding power is irrelevant.


I don't think it's desirable to have the maximum fluke area as possible for a given weight. Adding weight without adding bulk is usually not such a problem as adding more bulk. Anchor handling is usually limited by bulk, not weight, certainly in my case it is.

I think in soft substrates more area is very beneficial. Just as in firmer substrates a ballasted anchor like the Spade is slightly better. The outcome of course, not the theory, is what matters most and Steve’s testing bears that out
What’s your main anchor? I’m thinking it’s a Spade

[Anders]

Originally Posted by Dockhead

My experience with the Rocna in soft mud is the same as yours. Basically, it doesn't work in that kind of bottom -- forms a ball of mud around the anchor which can't set.

That's strange cause we anchor a lot in soft mud and it's what I consider the real strength of the Rocna.
It dives deep into the mud until only the short floating rope is seen. It certainly can bring up a lot of mud and often needs to be dragged in the water for a while.