Which size Rocna anchor for my boat?

[jeremiason]

Originally Posted by Capt.Alex

Let me start off by saying I have already made up my mind as to what type of anchor I am buying and do not want to debate the merits of one style over another....again. I want a Rocna. The problem is, what size. I always lean toward bigger is better, but at what point is it overkill? I own a 46' Hylas that displaces 27,777 pounds per the spec sheet.

Some cruisers decide that bigger is better... I am not a fan of that since it places undue strain on the windless and ground tackle.

We have a Catalina 47 that displaces 37,000 lbs when fully loaded for cruising. I have had it weighted twice during haul outs and both weights were within 300 lbs at two different yards.

Our primary anchor is a Rocna 25 (55 Lbs)., which held us in winds up to 50 knots with 5 to 1 chain scope on a sand bottom.

You will love the anchor, just remember not to back down too fast when setting the anchor or you will pull your windless off... The anchor sets hard and very fast.

I usually deploy the anchor using the wind to blow me down until the anchor is set then use the engine to back down on it.

[Stu Jackson]

Originally Posted by Capt.Alex

Is it possible that the bigger anchor will be significantly more troublesome to break free from the bottom?

Not if you use the right technique, get over the anchor and then raise it.

You might be interested in this, in reply to someone asking you wherre you were planning to cruise:

Anchor System Sizing Tables (Reply #6) Ground Tackle & Anchor System Sizing TABLES & SwivelsGround Tackle & Anchor System Sizing TABLES & Swivels

Good luck, fair winds.

[scoobert]

i plan to do a ronca that i will make myself, i am aiming for 105# or heavier, and my boat is about 19 tons.

[Kenomac]

Capt. Alex,

You have a nice boat with loads of stainless up front; why not explore a Quickline stainless steel Ultra Anchor for function and a seamless blend of good looks? Here's a couple of pics of ours, a 45kg model.

[Suijin]

Originally Posted by Kenomac

Capt. Alex,

You have a nice boat with loads of stainless up front; why not explore a Quickline stainless steel Ultra Anchor for function and a seamless blend of good looks? Here's a couple of pics of ours, a 45kg model.

Extremely good anchor, but at $2-3k they are pricey. Was talking to them yesterday at the boat show and the reasoning for why they have to be stainless was not entirely convincing.

As far as sizing goes, the OP should be sure he takes a look at the bigger anchor, in person, before pulling the trigger. The big Rocnas are enormous...it's like having a shield on the front of your boat.

[Kenomac]

Originally Posted by Suijin

As far as sizing goes, the OP should be sure he takes a look at the bigger anchor, in person, before pulling the trigger. The big Rocnas are enormous...it's like having a shield on the front of your boat.

Agreed. We had an oversized Rocna on our Hunter 450... the first thing people saw when they walked up to the boat, mostly because of the roll bar. $2k is short money compared to the cost of a Hylas; why make the anchor the first item seen? They should blend and function... 'just my opinion. Nothing wrong with some functional eye-candy.

[Jim Cate]

Originally Posted by Kenomac

Agreed. We had an oversized Rocna on our Hunter 450... the first thing people saw when they walked up to the boat, mostly because of the roll bar. $2k is short money compared to the cost of a Hylas; why make the anchor the first item seen? They should blend and function... 'just my opinion. Nothing wrong with some functional eye-candy.

Worrying about the appearance of one's anchor to someone walking up to the boat in a marina is a strange behavior for a cruising sailor. I guess that my value system is a bit different...

Cheers,

Jim

[redsky49]

... and a rusty, well used anchor provides some street creds, as opposed to the spit and polished dock-dwellers bow ornament.

My boat is a similar weight to the OP, and my experience with the Rocna has been 100% positive. At the same time, I am getting the sense that the anchor chain has a considerable influence over anchoring performance.

I am currently using 5/16" HT in order to reduce weight in the ends of the boat. I am pondering using 3/8" HT, not for the higher working strength, but for the additional weight it provides.

On the other hand, I never dragged with my old CQR so maybe there is also some art (or magic) involved in successful anchoring.

[Capt.Alex]

Thanks for all of the input. I drove to S. FL over the weekend to take a look at the Rocna's in person. The WM in N. Palm Beach had all of the on the shelf. In the end, I opted for the 73 lb. version. After seeing it in person, it appeared plenty large. The bigger one is absolutely huge. I have no doubt that the 73 pounder will do the job nicely. There was a significant price difference too. Those stainless jobs are pretty, but there is no way I can justify that kind of money. I was able to pick up the 73 Rocna with my Port Supply discount for under $800. I agree that I have a pretty boat, but I am still practical, and will take function over form every time. Thanks for all of the advice. I will report back with real world performance in the future.

[Fitsthebill]

I am a Rocna man myself. Of all the considerations I take the anchor most seriously. I have a 14000 ib Rawson 30'+2. The 2 being the new bowsprit /bow rollers and anchor storage. I am removing all teak from topsides. Those familiar know there's a 2" round cap rail. I will use the stainless tubing of that size to seize the schedule 40 to 80 plastic conduit I will substitute. The twin rollers at the bow give it options for a solid hook. I went with the 33 lb Rocna and a 35lb CQP but I plan to take any number of anchors including a North hill and fisherman as well as a fortress. I am a bit budget minded though and when you add up a fair bit of 3/8" chain and then the the windlass. It's a chuck of change. Those like myself who have seen the bumpy hanging by a thread and feeling like a sleepy head. Know why the ground tackle is so critical. The windless is one link in a chain that can have no weak links. I have an American made Bronze and SS manual 70 pounder I am considering. To tell the truth I dread topside weight. It was a big factor till I realized other powered windlass's weight 50 pounds add the batteries which are no low and cutting into her deck I have to say I am as always with a boat. There's a conundrum. Spend $1500 on a new one or try to make the like new manual work. It has a great gypsy and a drum for rope -both horizontal. I am sixty and I plan to go any and every where in every terrain and condition. If anyone wants to advise, I have always prided myself in that I ask...

[noelex 77]

Originally Posted by Fitsthebill

If anyone wants to advise, I have always prided myself in that I ask...

I think you have thought about your anchoring gear very carefully. I am sure your system will work well.
However, forgive me if I point out why I think your smallish new generation anchor combined with different anchor alternatives and a manual anchor winch it is not ideal.

Manual winches create a few problems:
1. There is a reluctance to re anchor. This should not be the case. The boat comes first etc, but it is fact of life. There are many situations where it is prudent to move. The easier it is, the more you will do it

2. There is a tendency to minimise the size of the ground tackle.

3. There is is reluctance to anchor in deeper water. Sometimes this is the best place.

4. If you do drag it is a very slow recovery to retrieve the anchor.

The fisherman and Norhill cover the the biggest weakness of new generation anchors. New generation anchors are much better than their older cousins at coping with weed, but a specialist weed anchor is still sometimes better. One way to overcome this problem is go large with the new generation anchor. A big heavy anchor will cut through weed better than a smaller anchor of the same design. With the specialist weed anchors they need to be very big anyway.

One of the great advances with the new generation anchors is that they are good in most substrates and even in weed they are OK. This eliminates the problems switching anchors. Switching anchors is not just frustrating it always a dilemma which anchor to use.

As an example I am just about to sail to new anchorage. The pilot book says thick weed is a problem here. Other cruisers have reported poor holding, but some believe this is due to soft mud.
I have anchored there once before and the anchor came up very deeply buried in soft mud with lots of weed on top so they are probably both right (I did not dive when I was here last time as I usually do as the water is deep, murky and it was winter)
The specialist weed anchors are very poor in soft mud, but this anchorage also has thick weed which is the very reason for carrying anchors like this.
A complicating factor is that the wind is predicted to change rapidly 180 degrees about 3am tomorrow. The specialist weed anchors are prone to catching chain around a fluke in these circumstances.

In your situation I would probably put out both the Rocna and Norhill in the hope that one will work better, but with the forcast this anchorage will be crowded especially in the shallower areas. Two anchors will make you swing differently with 180 degree change. ( I plan to anchor in the deep away from other boats, but I would not like to winch up that chain by hand)

This is where putting all your resources into large new generation anchor helps. This will still give good performance in weed and once through the weed it is the best anchor for soft mud.



There is no perfect anchoring philosophy, but a big new generation anchor with an electric anchor winch comes as close as I found.

[gunnado]

Go as big as you can manage, i do not regret it. I would still be happy to go one size bigger if I could handle it, not that I have needed more so far.

I have a 60 pound Manson supreme on a 39 ft beneteau. That is two sizes up from recommended.

It is only as hard to recover if it gets berried, so if it needs to hold more for heavier winds yes it should be harder to recover. But typically it is very easy to recover. Because it sets where you drop it it does not drag until getting fouled.

[Fitsthebill]

Thanks for the advice guys…
While there are weight restrictions. With the chain/anchors/ windless/ bowsprit- hook storage. My concern is paramount to being able to stop and sleep soundly on a good anchor system. I feel my ground tackle already exceeds my engine in weight and once more is up high where it adds to her roll.
Mitigation must be addressed to return her to her lines at some point. The bottom line is she is only a thirty footer and though the hook is the single most important issue for me it is not the only consideration.
At great inconvenience I have designed and am set to build a schedule 40 2" stainless bow pulpit that is doubled back and bolted to the deck and gunwale. It is also my anchor storage. Expense was not at all a consideration but weight certainly is on this.
I have a twin anchor option planned and as I think Noelex has pointed out some excellent points to consider in this area. I had wanted all 5/16 chain but again… This is a small boat.
Her chain locker is high in the bow. I am considering a sort of portable chain pipe to get that aft and into a deeper store well below water line.
Her high freeboard makes her already a liability in rolling. In a blow she will most certainly veer and put shock loads on her rode and anchorage. I am oversized on my anchors but will make light on other considerations, except for the bowsprit where I'll have a brick s-house bumper incase I strike pilings and such.
My whole reason for selecting the older stronger hand laid hull begin with the idea of her being bully. Her tankage and the lazarett where the spare anchors will be stored will I expect counter the extra weight in the bows but it all points to a shrinking magian between water and boot stripe...
I have had the big boat and am scaling back but there's a whole new set of problems with smaller. Water, fuel and provisions are varying weight factors underway while anchors and rodes remain the same.
Thank you for your advice Gunaldo and Noelex, Not enough can ever be said about ground tackle and I welcome anymore that can be added.

[WindLove]

Why is there so much focus on weight as opposed to surface area. As long as everybody talks about the "weight" being the most important thing, why don't we all go buy used car engines like the use for moorings and carry that around on your boat. After all, bigger is always better !?

[noelex 77]

It is mostly convention. We could talk about fluke surface area as an alternative, but a 1030 cm2, Rocna, does not mean too much to most people. If we talk about a 20kg (or 44lb) Rocna people can immediately comprehend.

It could be argued fluke surface area is a more valid parameter than weight and it does work better when comparing steel and aluminium anchors, but if we want people to understand without looking up tables we are stuck with weight.

This is not to say blade surface area is perfect. Like weight, anchors with the same blade surface area do not have the same, or even similar holding powers and for many people the actual weight is an important parameter in determining if their winch (or back) can raise the anchor comfortably.