Which anchor do I need for my boat?

[AccidentallyBeached]

Hi. I’m looking to replace our Bruce anchor for our Dufour Arpege (RIP Brucey. You were wonderful) but aren’t sure which weight we need. Our boat is 30-31ft and displacement is 6,600lbs… or 7,700lbs… or 3,600kg. Depending on which data you’re reading online. Our paperwork is inaccessible to us right now, however even on the older paperwork for the boat there are discrepancies of both size and weight. Quite the predicament!

We purchased the boat 2+ years ago and when we were replacing everything on it we found that the anchor was perfect as it was - but I cannot for the life of me remember its weight! Googling gives me very conflicting answers where some say size up and some don’t recommend sizing up. I’d rather size up if it helps, but I also don’t want to hinder its process.

Anyway, thank you! Much appreciated.

 

[GEM43]

Anchor Sizing Guide

 

[thinwater]

If the anchor was "perfect as it was" why are you replacing it? They don't wear out, really. You could regalvinize.

As for your question ... here we go again. You might try just searching the forum. Remember that weight is one factor, holding is slightly different, whatever you chose, it must actually fit on the bow roller, and the rode ropes vs, chain, size) also has an effect.

 

[Birdseye]

Have run the course on this issue with a similar side, maybe a bit heavier Starlight 35. Got rid of the Bruce and replaced with an early Rocna then swapped to a Manson Supreme again at 35lbs. I raced my boat which means the anchor has to be taken off the bow roller and put into the bow locker, something that my aged back didnt like. Manhandling 35lb at arms length under the pullpit isnt that easy.A pal with a 40ft Freedom schooner had always used a Fortress ally anchor of 10kg and he sailed all over the UK and a lot of long distance too. So I copied him and have again bought a Fortress for my new to me boat.,

I wont try to tell you that this anchor has any better holding than the Rocna or Manson but it certainly isnt any worse. What it does is to save my back. The holding of an anchor depends mostly on the surface area that digs in so the sharpness of the points and flukes matters a lot. You dig in with the boat itself so thats a constant whatever the anchor.

One other comment. If you have space which usually is the case then a mixed nylon and chain rode is best. All chain in heavy weather snatches as it pulls bar taut - no good for boat fittings and applies a "jack hammer" pull to the ancor where its bedded in. The nylon rode acts like a shock absorber

 

[LittleSister]

. . .
One other comment. If you have space which usually is the case then a mixed nylon and chain rode is best. All chain in heavy weather snatches as it pulls bar taut - no good for boat fittings and applies a "jack hammer" pull to the ancor where its bedded in. The nylon rode acts like a shock absorber

Or, arguably better still, an all chain rode but attached to the boat by a nylon stretchy 'snubber' (forget usual term) or bridle, (ideally run from aft cleat(s) via forward fairlead(s), for extra stretch capability) that can be deployed regardless of how much or little chain you have paid out.

 

[Birdseye]

Mybe little sister but you need a decent length of nylon to be a good shock absorber and whats more it need to be no more than 10mm / 12mm for his boat. Think bungy chord.

 

[doug748]

Hi. I’m looking to replace our Bruce anchor for our Dufour Arpege (RIP Brucey. You were wonderful) but aren’t sure which weight we need. Our boat is 30-31ft and displacement is 6,600lbs… or 7,700lbs… or 3,600kg. Depending on which data you’re reading online. Our paperwork is inaccessible to us right now, however even on the older paperwork for the boat there are discrepancies of both size and weight. Quite the predicament!

We purchased the boat 2+ years ago and when we were replacing everything on it we found that the anchor was perfect as it was - but I cannot for the life of me remember its weight! Googling gives me very conflicting answers where some say size up and some don’t recommend sizing up. I’d rather size up if it helps, but I also don’t want to hinder its process.

Anyway, thank you! Much appreciated.

You need a 10kg Rocna.. Just so happens I have one for sale. How fortunate is that?
Hardly been wet, £250, collect Plymouth.

Sorted

.

 

[RogerFoxTerrier]

My Rocna is the best £250 I've ever spent...

 

[Poignard]

A 35lb CQR.

Just so happens I have one available for £35. But you'd have to collect it from near Croydon.

 

[RogerFoxTerrier]

A 35lb CQR.

Just so happens I have one available for £35. But you'd have to collect it from near Croydon.

I have a 25lb CQR that's been on FB marketplace for the last three months for 20 quid - guess no one wants 90 year old technology any more. Strange.

 

[Chiara’s slave]

How about this one? Free to anyone who can carry it away, in the night.

 

[Tranona]

10kg New Generation (Rocna, Vulcan, Spade Manson, Knox etc) 6mm chain, 50-60m

No need to "size up" - the whole point of the new designs is to give greater holding power without excessive weight. If you look at the sizing charts for the anchor of your choice you will find your boat is right in the middles of the nominal 10kg size.

 

[thinwater]

How about this one? Free to anyone who can carry it away, in the night.
View attachment 195838

Or perhaps the OP wants to stay with a Bruce, just one size up.


Seriously, there are many new anchors that will perform better at a lighter weight, which matters if you do not have a windlass, which I'm guessing the OP does not. Viking would be my first choice (25#?), but there are many now.

I first started testing an researching anchors 30 years ago, due to a bout of shoulder and back trouble. That all got better.

My 34' PDQ (avitar) (8500 pounds) was happy with a 35# Manson and all-chain rode, and I use a ~ 10# alloy Excel with ~ 8 feet of chain backed by 100' of 1/2-inch rope on my F-24 (1800 pounds), which I like very much. So light.

 

[Neeves]

Viking Anchor have a batch of anchors scheduled to be fabricated in Ukraine (and the Ukrainians need all the support they can get (direct or indirect).

Viking's anchors are specified to a lighter weight vs vessel size because they use high tensile (and thinner) steel without compromising performance). In the same way Fortress recommend lighter anchors as their anchors are aluminium. Viking Anchors are also demountable - making them easy to remove from a bow roller (lighter) and store (demountable).

Viking weights are 'about' 50% the weight of the conventional anchor recommendation, so about 10kg, say, for the Viking or Odin against 20kg for a Rocna, Excel, Spade (or 10kg for the Fortress, aluminium Spade or Aluminium Excel).

Contact Viking Anchor and get your name on the 'I'm interested' list.

Jonathan

 

[RunAgroundHard]

Knox anchors will provide a smaller size for your boat than the current Bruce, if the Bruce was sized correctly.

… Our boat is 30-31ft and displacement is 6,600lbs… or 7,700lbs… or 3,600kg. …

Based on your information, from Knox Anchors

From Knox web site the KA13 would suit your vessel from the 33’ LOA, < 11t displacement. The KA13 weighs 13kg. As this is above your actual dimensions it will be able to hold higher than Knox’s base conditions noted below.
You could go a size down KA9 and for typical UK sailing conditions will have a very secure anchor. However, that would be borderline so you need an accurate displacement to be sure.

If you are replacing your current anchor with a high performance Knox anchor, you have the choice of using a lighter anchor of similar holding power or keeping to the previous weight and gaining much greater holding
power.

This Knox anchor size recommendations here are suitable for use in winds up to force 8 when there are moderate non-breaking waves. For more severe conditions choose a heavier Knox Anchor.

I changed out a 60lb CQR (27.2kg) for a Knox KA18 (18kg) and have been very impressed, having anchored in 40kt gusts, sheltered waters, 41’ LOA, 10t displacement. There is a template on their web site to check if it will fit.

Knox are also made in the UK. You will get a superior anchor to many while supporting a British business, if that is important to you. The materials and quality are excellent.

For clarity I have no association with Knox Anchors except as a customer.

 

[AntarcticPilot]

How about this one? Free to anyone who can carry it away, in the night.
View attachment 195838

We had two like that (ex-barge anchors) for our mooring in Dunbar harbour; they formed the bow mooring and we had lines to the harbour wall astern. They dragged one stormy day - but it was an exceptional storm, with at least one other boat in the harbour completely wrecked.