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Q&A: What Size Anchor Should We Buy?

Question: My wife and I have recently sold our 40ft Cambria and purchased an Able Apogee 50 for extended cruising. We were very happy with our 20kg SPADE anchor on our 40 footer and would like to purchase a SPADE for the new boat. At 50 feet and with an unloaded weight of 35,000lbs, we feel like the 30kg SPADE would be on the light side but the 55kg anchor would be overkill. Having used both sizes on your boat, we would greatly appreciate your advice. Despite having a hefty windlass, we are concerned that the 55kg model will be too difficult to manage.

Answer: You have great taste in boats. The Cambria and Apogee are two of my all time favorite designs.

I would go with the 55kg model SPADE. My thinking is as follows:

  1. I’m really not sure why a 55kg SPADE would be harder to handle than a 30kg, given that it will stow on a bow roller. If there is any problem with stowing the anchor in all conditions on the bow roller, that should be fixed with modifications to the roller and/or the addition of a chain tensioning device, whatever size anchor you have. I am not in favor of taking anchors off and stowing them below at sea, or not the best bower anyway.
  2. I am convinced that there is a non-linear benefit to bigger anchors once they get over 100lb. In other words, a 55kg anchor holds and sets way more than 1.8 times better than a 30kg anchor.

There is the drawback of more weight on the bow. But there is a way around that too: If you go up to Acco Grade 70 chain, or possibly G40, you can safely go down to 3/8″ and get a substantial weight saving that will more than compensate for the extra weight of the anchor. If your current chain is not G70 or G40 and is only BBB or Proof Coil and is only 3/8″ or less it is, in my opinion, too light anyway.

Note that with G70, you will need to order the chain with custom oversized links each end so that you can get a strong enough shackle to attach. With G40 you can use Crosby alloy shackles without compromising the overall system strength. I would recommend at least 300′ of chain. Of course this will probably let you in for a new windlass wildcat to fit the chain.

All of this could involve you in quite a lot of work and expense; however, I would still recommend it since there are few things that will contribute more to your cruising enjoyment and security than a really bomb proof anchoring system. That was certainly the case for us when we upgraded to the 55kg SPADE.

One other option would be to look at the Rocna line of anchors, which are very like the SPADE and seem to work as well. If you just don’t want to go to a 55kg SPADE, they have a 40kg model.

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mike clark

I think you are focused on spliting hairs. Use the bigest anchor you can carry on your bow (spade, cqr delta all about the same but bigger is better). Carry about 300 ft of the biggest chain you can. Weight of chain helpd hold the anchor parallel to the bottom so using a heavy anchor and light chain is not helping. Always use a 7:1 scope if posiable and never less than 5-1 and keep it simple using gear of suficent size to handel it easily.

Nicolas

Mike
John is right. He advocates a superior approach to anchoring. Read his material carefully. There is a fair bit to go thru. Points to look into are –
The best anchors are Spade & Rocnas. CQRs are simply inferior.
Main anchor should be heavier.
Heaviest chain is NOT advisable. True the increased weight provides more caternary but only to a point. Beyond this, in higher winds there is no caternary – ie the chain is bar tight.
The logic John & the Dashews advocate is maximize anchor, minimize chain diameter. Get the strongest chain – G7 (Acco) – to increase your margin of safety with small diameter chain.
Understand & use snubbers with an all chain rode.
An additional mine of info is the ‘Information Base’ in the Rocna anchor website.
I have no affiliation with Rocna, but two of my 4 anchors are Rocs.

Steve

John,
Most likely we will go with the Spade as our main anchor but still considering the Manson and the Rocna. Do you have any experience or knowledge on the supreme?
Thanks

Matt Marsh

I haven’t used a Supreme yet but I have inspected a few smaller ones (10-20 kg) in detail. If you order one, carefully inspect its weld beads, particularly where the shank joins the fluke and around the edge of the laminated tip, before accepting it. One stainless version I saw recently had a visibly defective weld… and it was still on the store shelf. The galvanized versions I’ve looked at appeared OK (of course, it’s hard to see what’s under all that zinc).

Incidentally, if you don’t know what to look for in a weld bead, I’d suggest bringing a metalworker friend with you to pick up any large fabricated anchor, be it Rocna, Spade, Manson or otherwise, just to make sure there are no obvious quality control slip-ups.

I agree with John on not using the quick-release slot. The last slotted anchor I used (a tiny Danforth clone) was a drags-with-every-wind-shift nightmare.

Steve

Thanks Matt and John,
And I’ll take my lovely wife to inspect. She was a welder in a Seattle shipyard before becoming a physician. She did a great job at Boreal inspecting last week.
I could not imagine using the quick release slot except on a smaller anchor if it was being used as a stern anchor.
I still have a few months left before crunch time and making sure I order all the new boat gear as I want it.
Thanks again.

Robert Reyes

Can anyone shed some light on why Manson makes the following claim ( and other manufacturers have not) :

“The anchor has been reviewed by Lloyd’s Register EMEA and it received a SHHP status, Super High Holding Power.
The first and only production boat anchor in the world to do so.”

I have a 44 lb with all chain , on my Crealock 34, and thus far have been happy with it’s performance.

Robert

ted wasserman

I would go for a A140 which is the overkill Spade on our Outbound 46 It only ways 41lbs and has never let us down from Maine to the Carribean. Spade just came out #1 best choice in the Feb Practical Sailor If you want an overkill ,then go for the A200. A stands for aluminum ,of course.