[C320-list] Reply to my inquiry from Rocna Anchors

[Jeffrey Hare]

Hi folks,

 

    As I mentioned yesterday, I posed some of the questions raised about the
Rocna demo video to the company.

They responded and I'll include those responses here.   Note that there is
one still frame from the video they sent that won't come through the email
which is interesting only to the extent that it shows that they really
didn't "test" the Rocna in different conditions from the rest as we
suspected.

 

  _____  

From: Rocna Anchors  
Sent: Wednesday, September 13, 2006 12:03 AM
To: catalina at thehares.com
Subject: RE: 

 

Hi Jeff,

 

Thanks for your e-mail.

 

Your comments (and those of your website visitors) are not the first we have
heard, although 99% of people are actually very impressed by the video and
it is only the vocal minority which gets a bit pedantic. The first thing to
remember is that we have no pretensions of this video being a comprehensive
comparison test documentary, as 1) such a video would have to be much
longer, well over an hour probably, and 2) we would have no credibility
being a biased party anyway, so why bother.

 

Rather, the principle motivation for the video is to demonstrate the
failings of the "old generation" of anchors, namely plows (CQR) and claws
(Bruce). Danforth we do not count as they are not a general purpose anchor
and should not be used as a primary bower. And we then show how the "new
generation" anchor, of course ours, works a little better.

 

I will sound a little defensive but can address a few of your points:

 

Type of seabed

 

In actual fact this beach consisted of sand mixed with broken shell for the
top several inches, but was quite hard clay underneath. Hence the reason we
were able to record such high holding forces for those anchors which did in
fact set (over a tonne for the 10Kg Rocna for example; you wouldn't get that
in soft mud). This means that the condition of the top layer was actually
irrelevant, but consider the following anyway:

 

[
http://www.catalina320.com/gallery/view_photo.php?set_albumName=rocna_anchor
<http://www.catalina320.com/gallery/view_photo.php?set_albumName=rocna_ancho
r&id=RocnaStillShot> &id=RocnaStillShot ] 

 

 

The above still from the video shows a more neutral shot and I have
indicated the testing location of the Rocna relative to the drag patterns of
the others. You can see where the waterline is.

 

In addition to this the "cameraman" made the mistake of filming the Rocna
from different angles and then doing the others more consistantly (from
right looking left in the context of that shot). This affects the lighting
and reflections off moisture in the sand.

 

So, the type of seabed was in fact practically the same for all anchors
tested. Except there were a few shots in soft mud, such as the one showing
the Bruce's hop-and-skip behavior, but that was not part of the
"comparison".

 

Speed of drag

 

Using a vehicle is problematic, I agree. A winch would be better. However,
our aim was to apply a constant force to the anchors, not a constant speed -
so as to simulate a boat, which once dragging does not move at a fixed rate,
but rather keeps accelerating (if the anchor does not hold).

 

A Danforth will never out-set a Rocna. (Did you know Danforths were
originally intended to be set by hand?!). In fact in the conditions of our
video, it might have never set at all, since the layered substrate as
described would present it with particular problems.

 

-------------

 

Most testing, even the neutral stuff done by magazines et al, is a waste of
time. It is never done properly. I am not going to claim that ours is any
better because frankly it isn't, for the reasons I gave at the top, although
at least we did pull multiple times and record an average. So as you say, it
would be nice to have a more comprehensive test with different bottom types
etc, but the fact is it simply doesn't exist yet.

 

It is possible that as we expand and become more successful the budget will
one day allow for a more in-depth production, but until then people are left
to depend on reviews and feedback as the most reliable source of info. For
example for our own part we can point to Steve Dashew's recent endorsement
after over a year of intense real-world testing, that from the Navy and
Coastguard, etc - and the customer will have to consider this in addition to
all the theory and demonstrations we present on our website in order to make
up their own mind.

 

I hope that helps.


Regards,

 

Craig Smith

Rocna Anchors

www.rocna.com

 

  _____  

From: Jeffrey Hare [mailto:catalina at thehares.com] 
Sent: Wednesday, September 13, 2006 04:34
To: enquiries at rocna.com
Subject: 

Hello Peter,

 

    I'm the webmaster for the Catalina320 International Association.   I
posted your article on our website for our members to read as requested.

 

There have been some questions recently discussed regarding the testing of
the anchor that I hope you could share with us.

 

   Many members watched the video demo and observed that conditions filmed
where the Bruce (claw) and possibly a Delta were dragged through sand, yet
the Rocna appears in the video to be dragged over and set in different types
of ground, specifically what looks like sandy/mud flats vs. relatively dry
beach sand for the others.

 

   While we were intrigued, and have been discussing the merits of this
anchor,  the demonstration video didn't appear to compare anchors in a way
that is scientific enough to be believable and to draw any conclusions for
comparison purposes.  This may have been a result of the video editing
process where perhaps some useful clips didn't make it into the final cut,
we can't tell for sure.  

 

   It would be great to see  true side by side comparisons, using a winch
with a fixed hauling speed, and strain gauges, etc, rather than a vehicle.
Some anchors seem to be pulled faster, whereas the Rocna is only shown being
pulled very slowly.

 

   Also some members commented that relatively dry sand tests aren't
indicative of how well an anchor holds in a seabed, but rather how much
surface area the anchor exposes.  In these tests,  a danforth would probably
outset and maybe outhold the rocna,  whereas in a sandy seabed the rocna
might burrow deeper and hold better than a danforth.  

 

   Tests of UNDERWATER grassy bottom, gravel bottom, hardpack, etc. are of
particular interest, since very few of us sail in waters where we can
actually see the bottom,  and carry more than one anchor, we'd like to see
the relative comparison in different surfaces.   It would require a very
scientific approach to show that a single anchor holds better than all the
others in all bottom types.

 

   The net result of this is that while lots of us are interested in this
anchor and want to learn more, the video seemed to undermine your
statistics.

 

Could you comment?

 

Thanks!

-Jeff Hare

 

Webmaster @ catalina320.com