How to choose anchor?

beautifulworld · 18 January 2013, 04:20

Hi guys, I just bought a Aquos 3.9 RIB, looks good, looking for some suggestions about anchor, any brands or any type of anchor, and also the range of price. The weight of my boat is 128kgs. Thanks advance!

j.i.wilson · 18 January 2013, 06:38

I have always used a Bruce type. Best holding power for weight, reasonably user friendly too. You can get none genuine Bruces which are a lot cheaper and, in my experience, just as good.

Just as important is the ground tackle, it is vital to use a good length of appropriate chain. Five metres would not be too much.

Anchor warp needs at least 3 to 1 scope, ie needs to be at least 3 times longer than the depth to be anchored.

Use stainless shackles, cheaper in the long run.

Boat jumbled are cheapest source of the kit.

jambo · 18 January 2013, 06:41

Completely agree with the previous poster only difference is that although the Bruce is an excellent anchor I prefer a Plough type.

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IanH · 18 January 2013, 07:57

I found these two websites A Boat Owners Guide to Choosing an Anchor and Anchor Selection Guide: Choosing an Anchor Type website good and there are many others if you google. For me, most important thing was suitability for location that I plan to use it (fast moving River and south coast) so local advice is good and inflatable friendly.

I soon discovered that different anchors have their 'fanboys' and their priorities and required properties may be quite different to your own.

Salty John · 18 January 2013, 09:59

If you anchor in mud a fluke type anchor such as a Danforth or Fortress will suit you. For anything else a plough such as the Bruce, CQR or Delta is a better choice. As others have said, at least 5m of chain and then nylon three strand or multiplait.

Size is a bit tricky, I'm used to selecting systems for larger keel boats where 'one pound per foot' is a good rule. For your application a 5kg steel anchor, or 3kg aluminium Fortress, with 6mm grade 30 chain would suffice, I would think. Perhaps others with more RIB experience could advise.

GJ0KYZ · 18 January 2013, 10:22

I'd second the comments about Danforths, they really do hold well in mud and sand. I have a CQR which is about as good an anchor as you can get in my uninformed opinion but their smallest one would probably still be a bit big for your boat. Maybe a Danforth with a good length of chain would be best for you.

beautifulworld · 22 January 2013, 23:34

Thx for all your suggestions guys, I can’t agree any more with the weight of the anchor. While I had to say that stainless shackle is little expensive to me, I have a really tight budget after I bought this RIB, after a little search and find Galvanised Steel Folding Anchor, it’s cheaper. Anyone knows anchor with this material? Is it durable? I know it maybe can’t be used as long as stainless shackle, but do you know how long it can last, and it’ll rust or not? Thx again for your help.

Peter_C · 23 January 2013, 00:21

This is a shackle. The shackle is used on the chain ends to attach the anchor and the rope. (Use a wire or something to keep them from unscrewing.)

There is no need for a stainless anchor, chain, nor shackle. Galvanized will last many years. Even if it rusts it will still last for years to come. If you lose, it or need to toss it due to an emergency you won't feel so bad if it is a galvanized setup.

jyasaki · 23 January 2013, 15:56

Make sure you wire the shackle pin so it can't come loose (because it will.) Stainless safety wire (auto parts stores that cater to racing should have it) works really well. Monel wire (chandler) is better but pricier (I think.)

jky

mister p · 23 January 2013, 18:03

I think shackle may have been mistaken for tackle. Stainless anchors very cool, galvanised the norm. Is you've got galvanised anchor and chain then can't see the issue with using galvanised shackles.

beautifulworld · 25 January 2013, 06:11

Thanks for all the advices, well, I have a last question, I want to buy 5kg steel anchor, but don’t know how long the chain and rope should be. Looking for suggestions, thank you for your patience.

beautifulworld · 25 January 2013, 06:44

Thanks for all the advices, well, I have a last question, I want to buy 5kg steel anchor, but don’t know how long the chain and rope should be. Looking for suggestions, thank you for your patience.

j.i.wilson · 25 January 2013, 08:13

Chain shoud be about 5m, but this is "flexible"

Anchor warp needs to be a minimum of 3 times the maximum depth you intend to anchor.

As said earlier, octaplait is best because it doesn't unwind, but it is expensive. I always just use 3 ply and replace occasionally. Helps if you put a swivel shackle between warp and chain.

I also endorse the need to "seize" (wire) all shackles, if they can come undone, they will!

Peter_C · 25 January 2013, 16:10

I too would say 5m of chain, but no less than 4m. In your other thread the guy said 3ft and that is not close to enough chain, even for a lake.

90m of rope should be enough but it depends on where you plan to anchor. I use 3 strand and it has enough stretch to be gentle on the anchor set, so it doesn't tear loose.

Buy a thimble eye also and install it in one or both ends of the rope. You can google "eye splice" for lots of info.

j.i.wilson · 25 January 2013, 16:55

It may also help to know what the chain is meant to do.

The anchor (any anchor) works best when it lies horizontal on the sea floor. The chain provides a heavy connection which provides a "buffer" between the anchor and the warp, which, being rope, tends to rise straight off the sea bed. It is important to have sufficient chain and warp to allow the anchor to lie flat on the sea bed. That's why you need several metres of chain and 3 times as much warp (rope) as the depth you intend to anchor.

Oh, and buy a book on splicing and rope work, it is not difficult and whiles away the time until the next boat trip.

Ian Wilson

beautifulworld · 29 January 2013, 05:59

Quote:

Originally Posted by Peter_C

I too would say 5m of chain, but no less than 4m. In your other thread the guy said 3ft and that is not close to enough chain, even for a lake.

90m of rope should be enough but it depends on where you plan to anchor. I use 3 strand and it has enough stretch to be gentle on the anchor set, so it doesn't tear loose.

Buy a thimble eye also and install it in one or both ends of the rope. You can google "eye splice" for lots of info.

thanks, it's very useful, and i google the eye splice, it's easy to be learned by this website Eye Splice | How to tie the Eye Splice | Splicing Knots.

beautifulworld · 29 January 2013, 06:26

Quote:

Originally Posted by j.i.wilson

It may also help to know what the chain is meant to do.

The anchor (any anchor) works best when it lies horizontal on the sea floor. The chain provides a heavy connection which provides a "buffer" between the anchor and the warp, which, being rope, tends to rise straight off the sea bed. It is important to have sufficient chain and warp to allow the anchor to lie flat on the sea bed. That's why you need several metres of chain and 3 times as much warp (rope) as the depth you intend to anchor.

Oh, and buy a book on splicing and rope work, it is not difficult and whiles away the time until the next boat trip.

Ian Wilson

thanks Ian, i bought a book from local dealer, i'm studying hard now

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