How heavy is too heavy?

[Arrandir]

I'm going to buy a new mainanchor for my new boat.
I have seen that most boats in the same size (32 feet, 7 ton) have 15 kg anchors. I would like to feel safer in the anchorages and think I will follow the heaviest-you-can-carry-and-afford-mentality.
How heavy do you think is too heavy?
I will buy at least a 20 kg anchor. 25 kg cost only $50 more, the extra safety will be worth the money, but is it too heavy?

[UNCIVILIZED]

So long as you don't have to spend $5,000 rebuilding your bow & roller to fit it (due to it's size), then 25kg is heavy. But why not? I'd surely do it given half a chance. Though I'd also be sure that I had 2 ways besides lifting it by hand to get it back onboard.

[Steve Bedford]

"So long as you don't have to spend $5,000 rebuilding your bow & roller to fit it (due to it's size), then 25kg is heavy. But why not? I'd surely do it given half a chance. Though I'd also be sure that I had 2 ways besides lifting it by hand to get it back onboard."

Excellent advice. Factors to consider are:
1. Will the anchor fit and if not, what will it take to make the modifications that will allow it to fit? You have to decide if it is worth it or not.
2. How will you handle the deployment and retrieval of the heavy anchor? Windlass or by hand? A heavy anchor that fits nicely on your bow configuration is easier to handle than the same anchor that is more of a challenge to make it fit. A windlass solves some of this but the final placement of s heavy anchor on the bow may require handling yourself (back to making it fit nicely on the bow).
3. Are the other components of the ground tackle matched to the working load of the heavier anchor? Some folks often forget that, especially with relatively inexpensive shackles.
4. Do you have chain or not and if so, how much? Remember that chain offers additional weight on the seabed. Some would suggest that a heavier anchor will allow for less chain and vice versa. That is a hot topic and I do not want to start that debate.

My recommendation is no one ever said "my anchor was too big to safely hold my vessel." Get the biggest and best setting/holding anchor you can handle.

Steve

[a64pilot]

My 2c, along with fit and capability to retrieve, how will it affect boat handling, will it cause hobby horsing for example?
I went with stupid big myself as it works for me and my boat isn't as prone to hobby horsing as some.
However intended use of the boat plays into it as well, if you only anchor out on weekends and therefore will never be in a storm front passage, why go with a big, expensive and heavy anchor?

[denverd0n]

Basically a summary of the above, but I see two main factors in determining if your anchor is too heavy:

If it negatively affects the balance of your boat then it is too heavy.
If you cannot deploy or retrieve it quickly and effectively then it is too heavy.

Remember also that the rode and all attachment points need to be sized to handle the anchor. That is to say, if the anchor is so heavy that it won't move, but the cleat you have it tied off to pulls out, then you do not have a good balance there -- the anchor is too heavy, or the cleat is too weak, take your pick.

[Shrew]

What kind of anchor are you looking at? Vessel weight and length are only two variables. Now those variables need to be used against the make/model of anchor you're looking at.

Every anchor manufacturer has a recommended sizing chart.

14,000lbs @ 32ft


Rocna: 15KG (33.069lbs)
Manson Supreme: 25lb (I'd consider the 35lb)
Delta (Lewmar): 22lb - 35 lb (I'd consider the 35lb)
CQR (Lewmar): 25lb - 35lb (I'd consider the 35lb)


25KG = 55.115 Lbs

That would be a very large anchor for that vessel. There is such a thing as oversizing your anchor.
While you don't want to drag, you also would prefer to ensure your anchor is set. There will be a point where the anchor and chain is so large, that the vessel can't reasonably set the anchor.

A buried anchor is far more effective than one laying on the seabed.

[denverd0n]

Originally Posted by Shrew

There will be a point where the anchor and chain is so large, that the vessel can't reasonably set the anchor.

Very good point!

[a64pilot]

I have heard the too big to set thing myself, it was brought up when I was looking for a Storm anchor.
According to the Rocna sizing chart I should use a 20 Kg, I had a 25 that set great, but wanted a Storm anchor so I got a 40 Kg, twice the size of recommended. It sets easily, I can't imagine how big too big to set would be.
It is tougher to break out and it does put a hurt on my VWC 1500 windlass, if it weren't a little oversized for my boat, then likely the 40 Kg anchor would have been too much.

[groundtackle]

Arrandir, you have recieved some excellent advise here.
I'd add: While fully loading a windlass is not something we want to do, someday you will. If you already have a marginal lifting ability, getting all that weight off the bottom in short order is trouble.
Is an oversize anchor actually set? it takes some hp. I'm sure it feels like it is.
32' / 7ton + type of vessel, rode and travel plans would be required for us to properly spec the appropriate size.
#4 Excel 16kg/37lb is on the cusp, would be fine with correct rode.
#5 Excel 22kg/47lb is more than enough, a big anchor.
The whole system needs to be sized correctly as these folk are saying.
ce

[S/V Alchemy]

Originally Posted by Arrandir

I'm going to buy a new mainanchor for my new boat.
I have seen that most boats in the same size (32 feet, 7 ton) have 15 kg anchors. I would like to feel safer in the anchorages and think I will follow the heaviest-you-can-carry-and-afford-mentality.
How heavy do you think is too heavy?
I will buy at least a 20 kg anchor. 25 kg cost only $50 more, the extra safety will be worth the money, but is it too heavy?

The anchor is only one part of the ground tackle system. You need to ask yourself several questions in order to make better (not best, which is unobtainable) choices:

1. Where are my cruising grounds? What is the general weather pattern of when I will be anchoring? I would give different answers for the mud of Chesapeake versus the Bay of Fundy, and a third answer for the channels of Patagonia or southern Chile.
2. What bottoms am I likely to anchor it? You may find two different main anchors of lighter mass make more sense than one if you have radically different bottoms where you want to be.
3. Does my boat have a lot of windage? Do I need a riding sail to reduce veering and therefore the odds I will side-pull the hook?
4. Do I have all-chain rode or chain-rope? Do I have a windlass? I'm a strong guy, but hand-hauling a 20 kg. anchor with all-chain rode would cause me to seek mechanical advantage.
5. Do I know how to rig snubbers and bridles? Do I customarily put out enough rode?

There's other considerations, too, but that list is a good start. If anchoring is a near-nightly thing, review your whole system, because odds are good you'll be caught out in rough stuff. If you are more fair-weather or have a lot of "outs" in the form of moorings and marinas to which you can turn, it's not so critical. Hope this helps.

[Cheechako]

20kg/44lb is plenty of anchor for a 32 ft boat. If you want holding power get a Danforth type, it will be twice the holding of the others and weight far less. But it's not all about that, or size etc. Everything on a boat is a compromise.

[Stu Jackson]

Anchor System Sizing Tables (Reply #6) & Why Swivels are a bad idea Ground Tackle & Anchor System Sizing TABLES & Swivels

[a64pilot]

Before I got my windlass, that 25 Kg Rocna was really more than I wanted, I really looked forward to dealing with it, especially if the wind was blowing.
Now its just push a button, a windlass is a life changing thing almost like an autopilot

[noelex 77]

Originally Posted by Shrew

There will be a point where the anchor and chain is so large, that the vessel can't reasonably set the anchor.

A buried anchor is far more effective than one laying on the seabed.

I have not seen this problem in practice. I don't think it is something to be concerned about.

With the exception of a rocky substrate, a bigger anchor will always hold more reliably, all other things being equal.

The best advice for a cruising boat is to fit the largest anchor that you can comfortably manage. Weight is an important consideration, but for most cruising boats the majority of the weight is in the chain. Going up one or two sizes for the anchor does not have much impact on total weight of the ground tackle.

[roverhi]

A 20k anchor is more than enough anchor for a boat of your length and displacement. A 15k anchor would be more than adequate. Even if you have a powered windlass, or some would say because you have a powered windlass, you are going to have to retrieve it by hand some day. As Cheechako said, get a large Danforth Pattern pattern anchor and use it for storm conditions either set seperately or in tandem with your normal anchor.

FWIW, When we were cruising had a 20k plow with 3/8" chain on 21,000# boat and never had a problem including a tropical depression with 50mph winds.