Anchor weight-need advice

Sailgunner · Jul 5, 2017

If your windless will handle it and it works on your bow roller why the question? I have a 55 # Rocna on my 410.

Parsons · Jul 5, 2017

I just made this decision on my Catalina 36, and chose the 20kg (44 lb) Rocna. Our light weights are similar, about 14,500 lbs, which is right on the cusp between the 15 kg and the 20 kg according to Rocna's guidance (http://rocna.cmpgroup.net/anchor-sizing-guide), which is designed for 50 knot winds in good holding conditions. Following several threads here, I was concerned about having the anchor stop the boat in case of emergency where the anchor would save the boat. The difference in dimension was only an inch or two in each direction, so either would fit on my bow, and most owners of C36s chose the 15 kg. I even emailed Rocna for advice, and they recommended 20 kg, but I'm suspicious of up-sell.

What sent me over the edge to buy the larger anchor was asking the hoist operator for a weight when the boat was splashed this spring - 18,000 lbs! That was before loading provisions, water, and water toys. According to that guidance, I am well within the 20 kg range, and I suspect that you are as well. I attribute the success of other owners with smaller anchors to luck in anchoring ground and the quality of the Rocna anchor. Another deciding factor was to imagine your bed suspended by a single line from the edge of a cliff - how much would you invest in the line and anchor at the top of the cliff. That's the decision you are making, after all.

Rick486 · Jul 5, 2017

An anchor is only too large if it materially affects the trim of the boat, or the windlass cannot recover it.

thinwater · Jul 5, 2017

34 pounds is MORE than enough for that boat. I have a 34' cat with far more windage, anchor in very soft mud, and have a 35-pound Manson + 100' of 1/4-inch G43 chain and a 35' snubber. You are already increasing your hold 50-100% by ditching the Delta and you already added chain. You didn't say if you used an adequate (at least 25 feet) snubber). Perhaps you've been scared by forum talk. It's a very conservative lot. But I think the 35-pound anchor will be good for you. Bigger is just more strain on the windlass and more to horse around when it comes up sideways.

If a 35-pound Rocna drags with a 14K boat, I suspect it was not used properly. Setting (procedure varies with the bottom), scope, bottom selection, long snubber. I don't understand the current "up-sizing" thing, when Rocna's advice is already quite conservative.

Gunni · Jul 5, 2017

Here's what world cruiser and master sailor Steve Dashew says. He likes the Rocna. Based on his experience I went up a size on my Manson Supreme and have found that he is right - a bigger anchor sets faster and will hold well on short scope.

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seadaddler · Jul 6, 2017

I have 2007 H-36 and had a 35lb delta and now 35lb Mantus both with 100' chain with my windless
And when pulling up my anchor I have my wife motor up slow to take the strain off the windless.
Nick

Stu Jackson · Jul 6, 2017

thinwater said:
I don't understand the current "up-sizing" thing, when Rocna's advice is already quite conservative.

Very true. The concept is to size your anchoring system:

Anchor System Sizing Tables (Reply #6) & Why Swivels are a bad idea http://c34.org/bbs/index.php/topic,4990.msg30400.html#msg30400

cmonroe54 · Jul 6, 2017

I have a Hunter 37 which is anchored with a Rocna 33kg. I chose this after reading everything West Marine had to offer. https://www.westmarine.com/WestAdvisor/Anchor-Testing

Don't forget the strength of the weakest link on the anchor system: the shackle.

YouTube has some good information. I recommend these two videos:
Ground Tackle — Sailing Uma [Step 41]
Hurricane survival anchoring tactics — Sailing Uma [Step 54]

Safe sailing!

shemandr · Jul 6, 2017

I had the 356 and had a lot of trouble with the Simpson Delta. I even upsized it and still had trouble. I think the problem is that the 356 and most of the chlorox boats are light in the bow and sail around the anchor quite a bit. This puts a surge load on the anchor and it can pull out. You can tell very fast that it isn't holding. You don't need to take bearings. You are headed downwind at about a knot. Port or Starboard side to wind. Go oversize. And we found salvation in the Manson Supreme but the Rocna or other spade anchors can do as well.
I don't think it's really about technique. I think it's hardware.

thinwater · Jul 6, 2017

shemandr said:
I had the 356 and had a lot of trouble with the Simpson Delta. I even upsized it and still had trouble. I think the problem is that the 356 and most of the chlorox boats are light in the bow and sail around the anchor quite a bit. This puts a surge load on the anchor and it can pull out. You can tell very fast that it isn't holding. You don't need to take bearings. You are headed downwind at about a knot. Port or Starboard side to wind. Go oversize. And we found salvation in the Manson Supreme but the Rocna or other spade anchors can do as well.
I don't think it's really about technique. I think it's hardware.

Do you use a rope or all-chain? Snubber on the chain? Bridle? Is there a dinghy on the bow? What else have you done to stop the horsing?

Horsing is a separate, very solvable problem. You should not solve it with a bigger anchor, you should get the boat to sit still. You can.

shemandr · Jul 6, 2017

OK, but I didn't write that post so that it would be about me. I used 50' chain spliced to three strand nylon, I think 5/8 ths. No bridle. Snubber when on chain. Not so much when the nylon rode was out. No dingy on bow. The riding sail was useless in stopping the horsing. We used a line from the anchor rode to a cockpit hard point to control the horsing. It was pretty effective but I've never been comfortable with anchoring complications which need to be removed while retrieving an anchor quickly in a tense situation. In a way I solved the problem by selling the boat. At least for me. It was in many ways a great boat. But it was not well behaved at anchor. It's been a few years but I haven't forgotten the sound of the anchor alarm going off. It went off a lot. I do think a bigger, better anchor is key to holding.

thinwater · Jul 6, 2017

As a cat user I set a bridle every night. Thus, I can't understand the concern about leaving in a hurry. It is just about dialing in the system. Since the line to the cockpit worked, it seems the answer was some manner of bridle.

There is no reason not to get a larger anchor, if you feel right about it. But it should not be to treat a different symptom. The rigging and adjustments to COE and CLR should stop horsing, the chain and snubber should moderate snatching and keep the rode low, and then the anchor can lie still and hold. Each for its job.

And why up-size and anchor design that is out-dated and wasn't working? I had a Delta (factory and too small) and went up a size to a Manson (any modern scoop design would have made me happy). That Delta never really set in the soft stuff. They don't.

Sailgunner · Jul 7, 2017

some call it hunting. These hunters swing back and forth a lot at anchor. Some try using riding sails to mitigate.

Anchor weight-need advice

Jimongee

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Sailgunner

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Jimongee

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Parsons

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Rick486

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thinwater

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Jimongee

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Gunni

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Hunter Ad Bot

seadaddler

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Stu Jackson

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cmonroe54

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shemandr

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thinwater

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shemandr

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thinwater

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Jimongee

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Sailgunner

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