Anchor Scope Cheat Sheet

[Nomad Willy]

Walt, we've been telling these cheapskates, (meant in the nicest possible way ), who pay thousands for electronic whateverelses, like money's no object, about the benefits of a chain counter, and it still falls on deaf ears. Yet they'll go to all sorts of lengths to make up a DYI way of counting length of anchor rode out. However, unless and until something prompts them to think outside the box and actually try one, they'll never listen, so we should just save out breath and let them keep doin' what they enjoy doin' in my view. Even though they are depriving themselves of the real joy of installing one for themselves, which I can vouch is actually very easy - even for me, and ex-medico with no tradie experience whatsovever..!

I mean, take Simi there. He's actually got one I think he has said in the past, and its sitting in a box. And he admits all it needs is a drill, and running some wires, and maybe a jigsaw or hole saw, and the rest is just follow the 'structions. How hard can it be. He's a fellow Aussie, renowned for DIY. Beats me.

PeterB,
Many people in the early days especially in the US like and gravitate toward independence. So there are the creators and thinkers and there are those that just go to the store. Here on TF there are more that go to the store. Can you count the threads about what is the best thing to buy? Of course not. There are just too many.
In the early days in America people were largely independent but not now. It never even occurs to many that one can solve problems by themselves. You can always buy something that will do it for you.

But in their defense they know that many have come before them w the same problem like keeping track of how much rode one has out. However in this case it shows (IMO) how many are willing to spend money to be able to anchor from inside the cabin. But strangely I don’t see you in this category Peter. Did you make you’re own? There was a guy in the Willard Boat Owners Group that designed and built perhaps the first one. Then there are some that just like modern trinkets .. like Codger and many others. So it’s more complex but I seems it does say something about oneself.

 

[Nomad Willy]

All useful ideas and I am sure we all have a version of one of them.

What stood out though was when Willy, the master of the anchor said he estimates the rode. And here I thought there was a science to comparing anchors, like using the same scope for different anchors.

Most of what I say is opinion Steve.
And I’m not hiding behind a tree when I say that. And I don’t anchor the same way every time. A lot has to do w the anchorage and weather. But w a very small anchorage I will anchor at 2-1. Taking a chance? Sure but everything in life is a gamble and about the odds. I could anchor at 3-1 but I may wind up on a big rock at 2am. It’s a matter of “estimating” what’s the bigger risk. But I’m definitely not one to stress about being as close to perfect as possible. Sorry
But thanks for the “master” part.
And Soo as soon as you change anchors the numbers all change.

 

[SteveK]

Eric, I probably do the 2 to 1 more often too in shallower water in calm conditions the chain is straight down. I recognise the rebel in you.

 

[Nomad Willy]

Steve,
Rebel? I’m more like an independent cowboy finding my own trail.
Or an old man w a young explorer’s mind.

With our tides “shallow water” must be about 30’ at low tide.

 

[Peter B]

Peter, The irony of your post is that prior to signing in today I had those exact thoughts!....It dawned on me that another approach to determining what depth a boat is in might be to use a long cord with a fluorescent weight on it. A crewman standing on the bow would call out "Mark Twain" when a depth of 12 feet is encountered....I guess one's approach to things like chain counters & depth sounders is all in the eyes of the beholder.

Walt, all I know is that Captain James Cook, who 'discovered' NZ, and was regarded as one of the most competent navigators and chart constructors would have 'killed' for a sonar, GPs, and yes, even a rode counter...

...Peter. Did you make you’re own? There was a guy in the Willard Boat Owners Group that designed and built perhaps the first one. It seems it does say something about oneself.

No Eric, I just bought me a relatively cheap NZ made counter here... CruzPro CH55 Chain Counter
and installed it myself. Took about half a day I think. Amazing sense of achievement though, when it actually worked..!
I also suggest it is way more fun, and even easier, than laying out yards of chain, to thread bits of something colourful, or insert plastic things into the links, or paint, every pre-determined length, which then get dirty, wear off, come loose, and tend to lose their colour over time, and can't be seen in the dark. Thereby necessitating shining lights up front to see them, and thus ruining ones night vision at the same time, when you could just look at a red illuminated dial..?

And that's coming from someone who had to be a bit of a cheapskate over what I spent on my boat. I did without radar - I did without AIS - I did without an auto pilot - but I would never go without my chain counter, just sayin'...

 

[ak-guy]

Let it out till the angle looks about right.

 

[Benthic2]

umm........

 

[Spinner]

A chain counter was the first thing I had added to Spinner after I bought her! So much easier to deploy the anchor from the pilot house when the counter is right there.

 

[Peter B]

A chain counter was the first thing I had added to Spinner after I bought her! So much easier to deploy the anchor from the pilot house when the counter is right there.

 

[Nomad Willy]

So Peter when I want to know if I should pay out more line instead of looking at the chain I should stumble along my side deck hurrying so I can get back before the boat swings too far, get the window open, shade myself from the sun and try and see my chain counter.

I’d rather just look.

 

[Codger2]

A chain counter was the first thing I had added to Spinner after I bought her! So much easier to deploy the anchor from the pilot house when the counter is right there.

Smart man!

 

[Codger2]

I’d rather just look.

Eric, i remember you posting that you retrieved your anchor by hand and I'm wondering why you decided to add a powered windlass?

 

[bayview]

Jesus, I've never seen so many ways to complicate what should be a simple thing.

Agree

 

[Shrew]

Interesting chart and technically accurate, but IMHO much of it isn't really useful IRL.

When would you ever be anchored at 2:1.....at ANY depth??

When would you be anchored at 10:1...at any depth??

I do mark our chain at 10 ft increments because anchorage depths will vary by the foot. (e.g 8, 9, 10, 11, 12, 13, 14, 15, 16) So marking at 25, 50, 75, becomes a guessing game at many depths.

1) Pulpit height and transducer depth (offset = 6 feet)

2) Add Offset to depth. Depth = 12 [12 + 6 = 18]

2) Multiply times Scope (target scope: 5:1) [18 ft x 5 = 90 feet]

The markers follow the order of the colors we learned in pre-school (R, Y, G, B)

1R = 10
1Y = 20
1G = 30
1B = 40
2R = 50
2Y = 60
2G = 70
2B = 80
3R = 90
3Y = 100
3G = 110
3B = 120
etc

No need to calculators or charts.

 

[jleonard]

When would you be anchored at 10:1...at any depth??

If someone is rafted with me I am at "about" 10:1

 

[Peter B]

So Peter when I want to know if I should pay out more line instead of looking at the chain I should stumble along my side deck hurrying so I can get back before the boat swings too far, get the window open, shade myself from the sun and try and see my chain counter.

I’d rather just look.

No, Eric, if you're one of those people who like to - or in your case, need to - stand at the bow to deploy or raise the anchor, a chain-counter is not for you. For me it was a no-brainer because there is no windlass switch at the bow, so that all has to be done from the helm.

But coming from years of yachting, (sail-boating to you), the ability to do it all from the shelter of the helm, and at the flick of a switch, was sheer luxury after years of having to stand outside hauling in the anchor, often in the rain and cold wind, on a bucking bow. Just sayin'...

 

[Nomad Willy]

So you fellers that anchor from the helm ... so how DO you tell how much rode is out? Just a wild guess i’m guessing ... you time the drop? Or just let it all hang out and assume the anchor depth agrees w the sounder. Then you’ve got to pay out scope. Seems to me the whole thing would be as they say .. a hit and miss. I never thought about it ... amazingly. Maybe I assumed you just used the buttons when it was poring down rain. I’m amazed. You actually anchor w/o looking at the rode .... wow.

OK now I know why several to many get excited about the counter.

 

[boathealer]

So you fellers that anchor from the helm so how DO you tell how much rode is out? Just a wild guess i’m guessing ... you time the drop? Or just let it all hang out and assume the anchor depth agrees w the sounder. Then you’ve got to pay out scope. Seems to me the whole thing would be as they say .. a hit and miss. I never thought about it ... amazingly. Maybe I assumed you just used the buttons when it was poring down rain. I’m amazed. You actually anchor w/o looking at the rode .... wow.

OK now I know why several to many get excited about the counter.

Easy.

That's why I use the 3ft lengths of bright yellow poly woven through my chain at 50ft intervals (picture in post above). I can see them going over the roller from the helm. I count 50ft, 100ft, done.

I also have a short frayed piece in one link showing when the anchor is JUST at my draft level on the way up.

I'm mostly at the bow unless the weather is REALLY nasty.

 

[markpierce]

When you are next to the windlass, one can observe the amount of rode/chain being deployed. So what's the horror with that?

Don't understand recovering rode and anchor remotely without knowing what is coming up organically and otherwise. ... I stand by the windlass, ready to pull of marine plants and removing mud.

 

[syjos]

When you are next to the windlass, one can observe the amount of rode/chain being deployed. So what's the horror with that?

Don't understand recovering rode and anchor remotely without knowing what is coming up organically and otherwise. ... I stand by the windlass, ready to pull of marine plants and removing mud.

I completely agree. I use a handheld remote to control the windlass while washing the chain. Observing the chain come up allows me to see which direction the chain leads, which enables me to communicate forward, reverse, starboard or port to my wife at the helm. I can also gauge the amount of chain twist and sometimes just stay in one place after the anchor lifts off the bottom to let it untwist.

The anchor is usually full of mud so as soon as the anchor nears the surface, I have my wife start driving out of the anchorage slowly with the anchor just below the surface to get the large clumps of mud off the flukes. When the large clumps are off, I bring the anchor in and finish washing it. Washing the big mud off when the anchor is in the roller makes a huge mess on the fore deck and bow so I try to get most of it off in the water.

Once anchor is clean, I attach the chain stopper. How do you do that if you're inside?

 

[Nomad Willy]

boathealer,
Well you better have good vision ... and keep your eyes glued to the chain on the roller. A good case for a far fwd wheelhouse.

What I like best about being on the bow is that I can see the line wiggling, vibrating or otherwise respond ing to being dragged across the bottom. Wild guesses can be very revealing. But at least I know something about what’s going on down there. Of course that is amplified by the fact that my nylon rode is very light compared to chain. I don’t have to wait until I see a tree rising up in front of the bow to know this won’t be an uneventful day.


boathealer wrote;
“I'm mostly at the bow unless the weather is REALLY nasty.“
I guess I assumed most were in this category.

I see syjos and his wife do about the same thing Chris and I do. With the exception of the remote. I suppose you could call my foot button a “remote”.

 

[Nomad Willy]

Eric, i remember you posting that you retrieved your anchor by hand and I'm wondering why you decided to add a powered windlass?

To save my body just like you suspect.
Hey that was a long time ago Walt.

Re just pulling the line over a roller on the bow I’d guess it cuts the required pull in half .. about. And a lot of energy is expended on keeping the wrap from jumping off the drum .. actually more often tying itself in an overhand knot.

 

[Nomad Willy]

To save my body just like you suspect.
Hey that was a long time ago Walt.

Re just pulling the line over a roller on the bow I’d guess it cuts the required pull in half .. about. And a lot of energy is expended on keeping the wrap from jumping off the drum .. actually more often tying itself in an overhand knot.

Should have bought a windlass.
But my rode smell is outside (actually it dosn’t stink .. as far as I can tell) and I don’t need to keep knocking the chain pile over. That must really suck in bad weather. And my whole system is light compared to chain. And my 5/8ths nylon Brait is expensive .. but cheap compared to chain.

 

[Shrew]

If someone is rafted with me I am at "about" 10:1

With all chain? OR a mixed rhode with nylon line. I could see 7:1 with a boat length of chain and the rest nylon line, but 10:1 all chain is A LOT of scope.

 

[jleonard]

With all chain? OR a mixed rhode with nylon line. I could see 7:1 with a boat length of chain and the rest nylon line, but 10:1 all chain is A LOT of scope.

Yes all chain. And I admit to being a "space eater".

 

[SteveK]

Yes all chain. And I admit to being a "space eater".

Curious, have you thought about putting a line with float to mark the location of the anchor. I am asking because the paid out chain may be at 10:1 but are you that far from the anchor or is the chain sitting in a pile on the bottom as added anchor.
In windless & current free waters of course. I think that there is a point where if the scope is not needed it will not be used even when payed out.
example 10:1 depth 50 feet, chain 500 feet.

 

[warren]

Correct scope

Hello,

I just thought I would share it to see if anyone else may need one or have one to share.

Not sure this one is the best but its up for grabs. I have the excel file as well if interested.

Jeff

The best system is one you understand,
but even more important is that the scope is based on the water depth (or max expected if tidal). Use what ever you want 3:1 5:1 etc. but only use the water depth .
There are some well known (mainly us) anchoring guides out there who have incorrectly interperated the coastguard advice , based on the naval guide . They suggest you should use the water depth PLUS the height of anchor roller above water and then multiply this number by the scope ratio 3:1 , 5:1 etc. TOTALLY WRONG. You should use the expected water depth only and add the roller height once only if you want.
Why does it matter? It's important in crowded anchorages that everyone has similar scope so when tide changes (sometimes wind too) the same separation between boat is maintained. Also important so you don't have excessive scope and drift into shallows , channels etc.
It's obvious but many folks don't get it!, nobody here of course!

Example for simple 3:1scope.
10' water depth, 10' roller height.
3:1= 30 ' rode in water. Easy and correct!
Or Incorrectly 10'+10'=20 x 3:1= 60' rode in water! crazy!

The boat with double the rode will be crashing into other boats in a crowed anchorage at tide change!
Why would you add the the roller height to the rode length in the water?
Should 2 identical boats one with a high bow roller and one with a close to waterline hawserpipe have different rode length in the water?NO!

You can add the roller height to your scope calculation ONCE if you want.

Thank you , soap box rant over!
Warren
Ps read guides i,e Chapmans , boat us , west marine etc they are so wrong!
Anchoring.com RYA.org.uk. ETC have it right.

 

[boathealer]

The best system is one you understand,
but even more important is that the scope is based on the water depth (or max expected if tidal). Use what ever you want 3:1 5:1 etc. but only use the water depth .
There are some well known (mainly us) anchoring guides out there who have incorrectly interperated the coastguard advice , based on the naval guide . They suggest you should use the water depth PLUS the height of anchor roller above water and then multiply this number by the scope ratio 3:1 , 5:1 etc. TOTALLY WRONG. You should use the expected water depth only and add the roller height once only if you want.
Why does it matter? It's important in crowded anchorages that everyone has similar scope so when tide changes (sometimes wind too) the same separation between boat is maintained. Also important so you don't have excessive scope and drift into shallows , channels etc.
It's obvious but many folks don't get it!, nobody here of course!

Example for simple 3:1scope.
10' water depth, 10' roller height.
3:1= 30 ' rode in water. Easy and correct!
Or Incorrectly 10'+10'=20 x 3:1= 60' rode in water! crazy!

The boat with double the rode will be crashing into other boats in a crowed anchorage at tide change!
Why would you add the the roller height to the rode length in the water?
Should 2 identical boats one with a high bow roller and one with a close to waterline hawserpipe have different rode length in the water?NO!

You can add the roller height to your scope calculation ONCE if you want.

Thank you , soap box rant over!
Warren
Ps read guides i,e Chapmans , boat us , west marine etc they are so wrong!
Anchoring.com RYA.org.uk. ETC have it right.

Um, I think you're pretty much wrong.

Never-mind the fact that in your example your resulting scope is 1.5:1, not 3:1 - remember those triangles you thought you'd never use in high school geometry?

Or maybe this was a troll and I fell right into it.....

 

[hollywood8118]

The best system is one you understand,
but even more important is that the scope is based on the water depth (or max expected if tidal). Use what ever you want 3:1 5:1 etc. but only use the water depth .
There are some well known (mainly us) anchoring guides out there who have incorrectly interperated the coastguard advice , based on the naval guide . They suggest you should use the water depth PLUS the height of anchor roller above water and then multiply this number by the scope ratio 3:1 , 5:1 etc. TOTALLY WRONG. You should use the expected water depth only and add the roller height once only if you want.
Why does it matter? It's important in crowded anchorages that everyone has similar scope so when tide changes (sometimes wind too) the same separation between boat is maintained. Also important so you don't have excessive scope and drift into shallows , channels etc.
It's obvious but many folks don't get it!, nobody here of course!

Example for simple 3:1scope.
10' water depth, 10' roller height.
3:1= 30 ' rode in water. Easy and correct!
Or Incorrectly 10'+10'=20 x 3:1= 60' rode in water! crazy!

The boat with double the rode will be crashing into other boats in a crowed anchorage at tide change!
Why would you add the the roller height to the rode length in the water?
Should 2 identical boats one with a high bow roller and one with a close to waterline hawserpipe have different rode length in the water?NO!

You can add the roller height to your scope calculation ONCE if you want.

Thank you , soap box rant over!
Warren
Ps read guides i,e Chapmans , boat us , west marine etc they are so wrong!
Anchoring.com RYA.org.uk. ETC have it right.

So how do you know what scope all the other boats around you have out?


Do the boats with rope rode have to anchor with only boats of a like rode also?


What happens if you get a rogue rope rode boat in the mix of all chain boats.. just imagine the mayhem



HOLLYWOOD

 

[jleonard]

Curious, have you thought about putting a line with float to mark the location of the anchor. I am asking because the paid out chain may be at 10:1 but are you that far from the anchor or is the chain sitting in a pile on the bottom as added anchor.
In windless & current free waters of course. I think that there is a point where if the scope is not needed it will not be used even when payed out.
example 10:1 depth 50 feet, chain 500 feet.
View attachment 106185

I don't like a float marking the anchor. Too easy for someone to foul on it, plus I don't mind someone swinging over my anchor. That has never been a problem in my 30 years of boating and anchoring.
I'm usually anchored in 10 feet or less and yes I know I have a pile at times.