advice on anchor and rope please.

[leonardgid]

Hello  raiders , what i would like to know is  what size/weight   sand anchor   does  one  need for a 15 foot  aluminium boat ,( i know about the 15 feet of chain ) also what thickness anchor rope and type    and how much of it  if someone needs to  use it in 50 metres of water , thank you all .   

[noelm]

Depends on the type of bottom, if it's sand, use one of those flat sand anchors, if it's reef, a reef pick with prongs is what you need, you will need at least 3 times the depth of water in rope, plus some reserve.

[frankS]

Sand anchor I would be looking at around 11 lb 5 kg and 8mm silver rope, 200metre roll , most of it will never get used but IF you really need it it will be there.

There used to be an old anchor rule of thumb where you would use 1 lb for every foot of boat, but this was largely overkill once you got past 12 ' or so.

With reef anchor the prongs should be skinny enough so you can easily bend them ( or rather straighten ) for recovery .

Also if you are venturing out to 20 metres or more I would suggest you learn about the buoy method of lifting your anchor.

Frank

[leonardgid]

14 hours ago, frankS said:

Sand anchor I would be looking at around 11 lb 5 kg and 8mm silver rope, 200metre roll , most of it will never get used but IF you really need it it will be there.

There used to be an old anchor rule of thumb where you would use 1 lb for every foot of boat, but this was largely overkill once you got past 12 ' or so.

With reef anchor the prongs should be skinny enough so you can easily bend them ( or rather straighten ) for recovery .

Also if you are venturing out to 20 metres or more I would suggest you learn about the buoy method of lifting your anchor.

Frank

thank you Frank very helpful, 

[JonD]

Its common to work on 3/1 ratio, so three time the amount of rope for the depth of water you intend to anchor in. In rough windy conditions this can increase to 5/1 or even 10/1. In saying that I get away with 2/1 with my sarca anchor but certainly wouldn't leave the boat to go for a dive with 2/1.

There are anchors that can be used that are very small but have incredible holding power such as rocna anchors and to a lesser extent sarca anchors. Ive used sarca anchors for years as they allow me to use far smaller lighter anchors and can hold in virtually all sea floor types (not lost one yet). Using them however does require you to use the correct size D shackle and recover them in the way manufactures recommend.

Rope thickness can depend on many factors, many styles of rope have different strengths for the same diameter. If you intend anchoring in deep water of 80-100m you may need a thinner stronger rope simply because of storage space. If you plan on handling the rope then 8-10mm might be comfortable in your hands. If you plan on using a float to raise the anchor in an alderney rig, then thinner stronger rope will do fine. Many people on a tight budget will use telecom rope, and have a cheap grapple and sand anchor, for me I find it a pain having two different anchors in a small boat. 

You can get rope at any boating store but this place has a huge variety of ropes which is quite interesting to look over https://ropegalore.com.au . You will see that some of the better 8mm anchor ropes might have a breaking point around 600kg while spectra in the same diameter has 6000kg, so you could actually use 2mm spectra fro over 800kg strength and carry your anchor line in your pocket!!!!!

[JonD]

Just realised you mentioned anchoring in 50m, check out alderney float anchor retrieval for those depths, Ive been using that style for over 40yrs. Never pull an anchor from a stern cleat.

 

Edited November 30, 2021 by JonD

[mob0103]

On 11/28/2021 at 7:53 PM, leonardgid said:

Hello  raiders , what i would like to know is  what size/weight   sand anchor   does  one  need for a 15 foot  aluminium boat ,( i know about the 15 feet of chain ) also what thickness anchor rope and type    and how much of it  if someone needs to  use it in 50 metres of water , thank you all .   

I know it doesn't really answer your question but an electric motor with spotlock is alos pretty good.

[leonardgid]

1 hour ago, mob0103 said:

I know it doesn't really answer your question but an electric motor with spotlock is alos pretty good.

i will look into it,  however beeing new tech  its prob going  to be out of my price  range . thanks for the tip .

 

[leonardgid]

16 hours ago, motiondave said:

I made up a video of a simple breakaway anchor set up, it allows me to use a sand mud anchor in rock.

 

thank you Dave, i am grateful for any advice , 

[leonardgid]

2 hours ago, JonD said:

Just realised you mentioned anchoring in 50m, check out alderney float anchor retrieval for those depths, Ive been using that style for over 40yrs. Never pull an anchor from a stern cleat.

 

great method  but i would not try it  untill i am really confident   with what ever boat i am using , thank you for the tips 

 

[noelm]

Anchoring in 50m of water is pretty deep for the novice boater, most would only be in less that 20 to start off, there's a lot of drag on 150m + of rope in any sort of current

[antonywardle]

A boat that small, I think you'd be ok with the telstra rope. It's breaking strain is around 250kg.

Its pretty cheap too.

 

 

 

[leonardgid]

On 12/1/2021 at 5:21 AM, antonywardle said:

A boat that small, I think you'd be ok with the telstra rope. It's breaking strain is around 250kg.

Its pretty cheap too.

 

 

 

ive got  quite a bit  of that , i will use it as back up  ,    first 50 metres i will use 10ml  silver rope , thanks for the advice.

 

[leonardgid]

On 11/30/2021 at 4:29 PM, noelm said:

Anchoring in 50m of water is pretty deep for the novice boater, most would only be in less that 20 to start off, there's a lot of drag on 150m + of rope in any sort of current

i was thinking middle harbour 

[leonardgid]

On 11/29/2021 at 10:22 PM, motiondave said:

I made up a video of a simple breakaway anchor set up, it allows me to use a sand mud anchor in rock.

 

i just watched  your video  , very helpful  , i will do the same thing with the reef anchor  also , Thank you Dave .

[leonardgid]

On 11/28/2021 at 8:57 PM, noelm said:

Depends on the type of bottom, if it's sand, use one of those flat sand anchors, if it's reef, a reef pick with prongs is what you need, you will need at least 3 times the depth of water in rope, plus some reserve.

thank you