Anchor Weight

Boat: 48 ft
Weight: about 48K

Right now I have a 40lb Danforth anchor with all chain rode.

I saw a 45Lb SS swivel plow and was wondering if this is heavy enough to hold ASD?

Personally, I'd go bigger. I think with anchors, size matters. I had a 45 lb stainless plow on my Grand Banks that dragged, and replaced it with an 80 lb Manson Supreme. It has never dragged.

Personally I'd go with bigger. IMO. You'll have a lot of those.

I'd go bigger as well. We have a 60 lb. Manson Supreme. That was as big as I could fit on the bow without modification. And I am not entirely sure my old windlass could lift much more.

There are several sizing charts out there that can be used as a guide in selecting an anchor. I believe BoatUS has one too. Some sites even include various sizes for different types of anchors. The American Merchant Seamans Manual suggests that the Navy uses 1 to 1.5lbs of anchor per ton of vessel plus an all chain rode. Talking to a few naval architects a while back when I was at school, they would agree with twistedtree and go a little bigger using a safety factor of 1.5 to 2 above the recomended size. Maybe the key is to find something that gives you peace of mind.

Unless you anchor where there is swell or other waves windage is the factor to be considered. Not weight.

Anchor type is the next consideration re anchor size. I just bought a 33# anchor for my boat that is only 30' and has no FB. The anchor is a Claw and their performance (holding power wise) is lower than most so I went over sized w 33#. I'd go 18 to 22lbs w most other anchors. My smallest is a 13lb Danforth that came w the boat. It's never let me down and I've anchored in 35 knot winds w it. Non burying types need to be about twice the weight (size) of modern anchors. So if I had a Navy anchor I'd be looking for a 45 to 50# unit. A Dreadmought 45# and a Forfjord 40#. My friend in Alaska has a Forfjord on a boat almost exactly the same as mine and his Forfjord is 65#. That's over kill but not ridiculously heavy.

So my point is that windage is the biggest thing to overcome and the weight of the anchor is determined by the bottom where you anchor, the performance of your anchor and how much air drag your boat has in winds you intend to anchor in. Plus a bit of safety factor added to the weight of the anchor. The two biggest variables are bottom type and anchor design in that order.

THEN comes weight for a specific anchor design. If I had a 22lb Rocna on a good bottom w normal scope I trust it up to 50 knots of wind w my boat w little or no waves. It would take a 44# Claw to do the same. So IMO either the 22lb Rocna or the 44# Claw will do the same job. There's other lesser variables like the Claw requires less chain and costs much less ect ect.

But if you use a chart put out by the anchor manufacturer make sure you you consider the wind rating for their design of anchor and factor in whether or not your boat has more or less windage than the average boat.

The above is strictly my own opinion and there are many other opinions but experience will make you comfortable as time goes on. I've weathered two 50 to 55 knot gales (8 hrs and 1.5 days) w one brand of anchor and w a forecast of 50 knots I'm going to be inclined to use that anchor. Using any other would be an experiment despite the ravings of others.

And there are many other considerations regarding anchor size.

I would say boat motion has a greater effect on anchors than almost anything...not wind.

I have seen boats try and anchor unsuccessfully in surf that have used the same setup in screaming winds of 40+ knots. Unprotected anchorages where surge is allowed to build scare me way more than just anchoring in even 60+ knot winds with no surge/fetch.

psneeld said:

I would say boat motion has a greater effect on anchors than almost anything...not wind.

I have seen boats try and anchor unsuccessfully in surf that have used the same setup in screaming winds of 40+ knots. Unprotected anchorages where surge is allowed to build scare me way more than just anchoring in even 60+ knot winds with no surge/fetch.

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I agree. Surge is what you need to plan for.

Well, I am setting up to cruise the west coast from Alaska south to southern CA or Mexico and will be doing a lot of anchoring in the inside passage with strong currents, but protected anchorages. I have a friend that is currently up north making his way up the passage. He anchored in Oliver Cove which is just north of Bella Bella BC. He has a 60# claw with an all chain rode. He got it stuck on a rock (he thinks) and ripped his bow pulpit off! Just his luck.

So in an emergency I may have to anchor in open Pacific water, but I also don't want to over stress my windlass. I also have no experience with a windless so please forgive my ignorance.

I'd be look'in for a 85lb anchor. More if it was a Claw.

The Claw has it's advantages up north. Cheap to replace and many anchorages have lots of logging gear on the bottom. In a gale and on a mud bottom you will probably drag but unlike most perceive it it isn't the end of the world. With a good anchor alarm it's almost always just an inconvenience. Like resetting in horizontal rain in the middle of the night or idling in gear w lots of wind.

A 100lb Manson Supreme would be perfect except for the possible replacement cost. And ther'e not as bad as many.

At 48K lbs Alaskan Sea-Duction is a lot of boat. I agree with the others, get a much bigger anchor. 40 kg as a starter.

Give some thought as to how much you could lift if your windlass fails.

Here is a site that is good for sizing anchors and rodes. It use to have a excel that calculated using diffeernt variable. Tuning an Anchor Rode Probalbe more than you wnated!

As a reference: The Eagle is 58 ft, 80,000+ lbs with an all chain rode and the calculation staid a 98 lb amchor. However the scope 5+ and the bottom condition change the results quite a bit. 5 times scope results in a 21 degree staight on pulling.






The limiting factor will proable be your windless.

By "swivel plow" do you mean a CQR type anchor? If so 44lb is what Lewmar shows as the "one up" size for your type boat. Is your Danforth a standard, Deepset, or High Test? Depending on which, it may also be the right size. Weight to a large degree is a function of design.

caltexflanc said:

By "swivel plow" do you mean a CQR type anchor? If so 44lb is what Lewmar shows as the "one up" size for your type boat. Is your Danforth a standard, Deepset, or High Test? Depending on which, it may also be the right size. Weight to a large degree is a function of design.

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You are correct. The 40lb Danforth I have is from WM and is the standard design. This boat was kept in the Sacramento/Stockton CA waterways, so not much anchor needed as I only have 120 feet of chain rode. But when you look at Lewmar they do recommend a 44# anchor, so I was wondering if that was enough. Hence the reason I am asking the TF experts who have some experience more than I.

I am starting to look at this because of what happened to my buddy up north.

On Amar la Vida, I have a 60lb CQR and a 43 lb Danforth as a back-up all chain rode and a 25lb Danforth as a third "lunch hook".

This is what I got from Lewmar on a plow:

Thank you for contacting Lewmar.

I normally recommend two anchors when people ask me this question.

The first one is the most appropriate and then I also recommend the next size up.

The next size up is a good way to go as the pricing is not too much more nor is the weight however it will have more holding power and you want to have the power and not need it rather than need it and not have it.

The smallest I would recommend would be the 55lb as the most appropriate but I would suggest going with the 70lb.

If you have any further questions, please feel free to contact us.

Josh

Lewmar, Inc.
Phone: (203)458-6200, ext. 202
Fax: (203)458-2270
Email: josh@lewmar.com
Website: www.Lewmar.com

Wifey B: Size definitely matters and the only ones who tell you otherwise don't have it. Well, up to a point. If it won't fit, then it's a problem (In your windlass, silly).

To us it's look at the chart and go one size larger than they say. Looking at anchoring in the Pacific, it's really to me as much chain and anchor as you can accommodate and handle. You do need to make sure not to overload your windlass.

Why not work it backwards.

The largest anchor your bow roller can handle , or the largest your windlass can handle , and forget about the watch fobs.

WE chose 60lbs as easy to handle so a pair of rollers allow selection between Danforth or CQR , and there is no problem, one is always ready to deploy.

Chrome the watch fobs and use then as a basis for a nautical lamp.

Fred let's see a pic of your winch.

When we anchored in the 50 knot blow on our last trip there were two other boats in the anchorage. A Krogen with a Bruce that had caught a small tree. He dragged. We had to move because of his dragging nearly into us. The 45' sailboat moved once because of the dragging Krogen and he didn't drag. He had a CQR.

There is an add for Danforth in my 1953 Motor Boating magazine that claimed the Danforth had the highest holding power of any other anchor. Now over 50 years later that's still true.

I am old school, so carry 3 anchors, Forjord, Danfoth, QCR and two rodes, all chain and rope with chain. Old school was you carry at two anchors, QCR, plow, and a navy, Danforth for difference bottoms, back up and if needed both were deployed. New school is one anchor for all purposes, but you should still have a back up just in case. If you walk the dock, you will still see many boats with two types of anchors. However, many are now Bruce instead of QCR.

According to the site, tuning the rode, all chain rode, 5+ scope, and the bottom are equal if not more important than the anchor. If I had to choose between a heavier anchor or longer/more rode, I would choose rode so the angle of pull is more straight on, and the weight and drag of the chain helps. If heavy blow, would deploy two anchors

manyboats said:

Fred let's see a pic of your winch.

When we anchored in the 50 knot blow on our last trip there were two other boats in the anchorage. A Krogen with a Bruce that had caught a small tree. He dragged. We had to move because of his dragging nearly into us. The 45' sailboat moved once because of the dragging Krogen and he didn't drag. He had a CQR.

There is an add for Danforth in my 1953 Motor Boating magazine that claimed the Danforth had the highest holding power of any other anchor. Now over 50 years later that's still true.

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Funny how they're all always talking new and improved and in my boating career I can't really see much difference at all from the time I started to today.

And while we don't anchor often, when we do, I worry a lot less about my anchor holding than I do all the other boats around.

>Fred let's see a pic of your winch.<

Its not the winch that is of interest , it is the fact it is HYD powered.

No white smoke , when overloaded .

When it stops , overloaded ,all that is required is another 200 rpm on the engine .

Any Hyd windlass has the same delightful features.

On our commercial boats we have extra heavy duty everything - from windlassess to anchors. If your bow roller can handle a heavier anchor and the windlass can winch it - then go with a 31kg anchor. If not, then stay with a 18kg model.

I computed one time that the four anchors we carry weigh more than a 57 Chevy.

Well this guy thinks size and weight matter.

I was down in Seattle yesterday at Hatton Marine and the Salmon Bay Cafe and saw this serious motorsailer.

I saw this monster Forfjord taking the first pic but when I walked over to the boat I saw the big Navy anchor on the other side. You can see the Navy in the first pic. Guy must have 600lbs of anchor. Judging from the anchors he probably has all big chain too.

I looked for the "Interesting Boats" thread but couldn't find. Decided this would be an appropriate place. Another pic shows a boat in Craig AK w a 500lb Navy anchor. Some guys thing bigger is better no matter how big you go. As many of you know I'm dead set against excess weight.

Is this really a serious discussion???

If I could easily handle/store (with or without a windlass) a 5,000 pound anchor...would I????

Obviously...so the question for intelligent people is what will do great for me in my normal and occasional anchoring situations?

Not many of these discussions seriously answer specifics...just generalities which are just about meaningless.

Send boat size, weight, approximate windage...the places you MAY anchor and be exposed to extremes...and then only the most basic recommendations are meaningful...the rest is just another forum discussion. vary from those specifics and it's a whole nother discussion.

psneeld said:

Is this really a serious discussion???

If I could easily handle/store (with or without a windlass) a 5,000 pound anchor...would I????

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Only you could answer that question?

Oh, were you not being serious?

I think looking back through the thread there were helpful responses. Far better than most anchor discussions go.

I will stick with my wife and say the chart plus one. But also look at the capacity of the windlass he has and see what it will handle. I doubt seriously it will accommodate a 5000 pound anchor and hopefully it's just sized to handle a larger, but still sensible size for his boat.

BandB said:

Only you could answer that question?

Oh, were you not being serious?

I think looking back through the thread there were helpful responses. Far better than most anchor discussions go.

I will stick with my wife and say the chart plus one. But also look at the capacity of the windlass he has and see what it will handle. I doubt seriously it will accommodate a 5000 pound anchor and hopefully it's just sized to handle a larger, but still sensible size for his boat.

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Thank you for making my point...

There are hundreds and hundreds of boaters here on the forum deciding from post to post just how serious any post or thread is. One persons opinion means almost nothing. 999% of the opinions will never be communicated to anybody. This is a forum on the internet and most of what goes on here will be in the minds of individuals.

manyboats said:

There are hundreds and hundreds of boaters here on the forum deciding from post to post just how serious any post or thread is. One persons opinion means almost nothing. 999% of the opinions will never be communicated to anybody. This is a forum on the internet and most of what goes on here will be in the minds of individuals.

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999% is a high percentage. So for every one opinion here, almost ten of them will not be communicated. Wow.

Years ago there was an outrageous talk radio host who just did a show of humor. Every once in a while he'd get a caller saying he should do topics, tackle serious subject. He responded that early in his career he had, but not one time had any issue ever been resolved on talk radio.

Now honestly I think a lot of good information is exchanged on this site. And some good humor at times. Only occasionally do we wander to 5000 pound anchors and 999% results and when we do, it's generally not a tragedy that is going to destroy our world.

BandB said:

Now honestly I think a lot of good information is exchanged on this site. And some good humor at times. Only occasionally do we wander to 5000 pound anchors and 999% results and when we do, it's generally not a tragedy that is going to destroy our world.

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Now, that's the right attitude, right there..!