Rocna Anchor

Last year (2009) we stayed on the hook (at anchor) in the Ramada Cove anchorage. When we first arrived, we took our time to make sure the anchor was well set and allowed plenty of scope (7:1).

A couple nights later, we spent a semi-sleepless night when a strong wind piped up and started pushing us toward shore a bit. Of course it was at 1am.

Our 20kg Bruce held, but to be sure required staying in the cockpit to be certain that we had time to do anything that might have been needed to keep us off the now lee shore. The next morning we were in about the same location in relation to the shore as we started but when retrieving the anchor, we found it in a different place than it started.

Bruce anchors are good anchors and we have used it many times without dragging. However, with all the new generation anchor designs today, we saw no reason to stay with old generation anchor designs when they have clearly been out-classed in current day tests and decided right then and there to install a Rocna anchor as our primary anchor and move the Bruce to secondary. The Rocna has a great holding reputation and that’s what we need given all the places we plan to visit.

In April, 2009 we decided to seriously pursue purchasing a Rocna anchor. On the Rocna Web site, they have a full size pattern that can be downloaded and transferred to cardboard. The cardboard cutout plus their charts of anchor size and boat size helps to figure out proper placement and size.

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We have two anchors on the bow, so we need to make sure they can ride together.

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We order the anchor and have it shipped to Mail Link Plus, our mail forwarding service in Las Vegas, Nevada. We order a bunch of stuff from San Diego Marine Exchange and have it shipped there, too. West Marine has a location just outside Vegas, so we have more boat related stuff shipped there.

When everything we ordered reaches it destination, we jump on the Tufesa bus and take the 28-hour ride to Las Vegas. We make the most of our time in Las Vegas and do some more shopping!

We end up with five pieces of luggage, plus the anchor, computer, and carryon luggage. We wait at the Tufesa bus station wondering how much we’ll have to pay in excess weight fees.

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The bus driver checked our luggage all the way to Mazatlan. Other passengers stare at the anchor wondering what in the heck it is.

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We arrive in Mazatlan nearly 30 hours later. No problems at the border. Got the green light and walked right on through.

Now that the anchor is on the boat, the anchor mount design begins in earnest. We hire Rick, on s/v CAPE STAR (AKA Mazatlan Marine Services; formerly C & C Marine Services) to design and install the stainless steel mount)

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Rick and Rick remove the bolts on the bowsprit in preparation of  the new fabricated mount.

Rick (CAPE STAR) takes the rollers and other parts to the shop and begins fabricating the Rocna mount. The pulpit stays with the boat but is just sitting there not bolted down.

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About a week later, Rick (CAPE STAR) returns with the new mount and instructs his team what to do next.

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The anchor mount requires welders, CAPE STAR’s instructions, and Joe’s “supervision” (s/v YANCEY).

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The Windless pulls the anchor up easily and while in the slip it appears to fit in the mount OK. We have to test it at anchor, but so far, so good.

Rick (LA VITA) has since wrapped the bobstay with reinforced water hose to protect the bobstay from the Rocna when it is retrieved.

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February 5, 2011
ROCNA ANCHOR UPDATE

When we used the Rocna for the first time, we were in for some surprises.

First, I was used to feeling the anchor drag a short distance across the sand bottom before it set. With the Rocna, by the time I had let out scope, secured the chain a bit and reached the chain to feel that movement, there was no movement. The GPS didn’t move more than an 1/10 of a second and then returned to the original position.

The Rocna is said to be designed to set within its own length. It did. It held at cruising RPM. We’ve heard that in heavy grass it has a problem and that when it doesn’t set in that condition, bringing it up will clear the path since it takes out the grass. Then you just look for the path it took out and reset the anchor in the sand that it has uncovered. Can’t vouch for that but it is what we’ve heard.

The first time we raised the Rocna, it was difficult to break out when compared to the Bruce that was our primary anchor and is now our secondary. I used the rise and fall of the boat to do that. When the anchor got within visible distance it was covered with sand and mud estimated at over six inches deep. There was a mud/sand cloud all around the boat and it took a while to get the mud/sand cleared off the anchor before bringing it onboard.

To date, we have had similar experiences every time we have used the Rocna anchor. It digs in (in its own length), sets hard, and stays there.

Since we have a bowsprit, the Rocna is difficult to stow. The company we had do some modifications did two things. First they moved the secondary anchor roller back towards the bow about 6 or 8 inches to add clearance between the two wide anchors so that either could be deployed or retrieved without interfering with the other. Sounds good but we haven’t tested that yet.

Secondly he added a “fork” for the Rocna “roll bar” to come up into and a sheet of stainless steel to protect the wood bowsprit. This worked reasonably well in the slip. The anchor seemed to slip around the bobstay on the way up and down. It came “home” into the fork every time. No problems.

Out of the slip it was a completely different story. The Rocna hangs up on the bobstay every time it goes down. It wants to come up in the wrong position, either ahead of or behind the “fork”, each time it is raised. I have to “play” with the chain to spin the anchor to get it in a position to miss the bobstay each time. This is not a good thing to be sure.

To be fair in this discussion, I installed a section of hose to protect the stainless steel bobstay from damage as the anchors were lowered and raised. It has always been “in the way” no matter what anchor we used. The hose protection was not in place when the tests in the slip were done since the correct size hose was not available locally but the fact that I was going to do that, and it was known, the design should have allowed for the bobstay hose protection.

The reason for all that work while anchoring is the design of the “fork” as envisioned by our fabricator. We had originally asked for cheeks and another roller and had pictures of successful installations. He thought that the “fork” would be easier to do and less expensive and would work just as well. Since he had experience doing modifications for these anchors (and much larger ones at that), we went with his design. Unfortunately, that is our problem today and will have to be completely redone somewhere “down the road”.

When that work is done, we will have the existing bow roller installed below the anchor platform over the bowsprit. It will be angled outboard slightly. Attached to that will be “cheeks” that will extend out and down and at the lower end, have another bow roller.

The outboard angle will allow it to be raised and lowered without contacting the bobstay. It will allow the anchor shank to sit more flat above the anchor platform. It will also require a turning block of sorts to set up the chain for a straight pull for the windlass. That can be done by using an off the shelf stern anchor rode fitting designed with two rollers guiding the chain. The same will be done for both the primary and secondary anchors.

To view the photo album for this post, click on the camera,

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