Anchoring rights

[Chris_Robb]

Invariably when I wake up in the morning in an anchorage in Greece when there is little or no wind I am right over my anchor, sometimes can actually see it from the boat.

Thats precisely the point, and the subject of this thread. Its was about anchor buoys and knowing where your anchor is. Post saying that this is over complicated and that it is simple because the boat is always lying in a line to its extended chain and anchor have just utterly missed the point.

The aim is to try to provide new comers to an anchorage with an idea as to where your anchor is - to help them set theirs - so that they will not be a danger to YOU. As you say, after a night drifting around you can have little idea whether its in front , behind or to the side. Modern technology comes in to play here with plotters etc but at their amp consumption I would not be happy to have on continuously. The Mobile is the obvious answer as you can have it by your pillow if necessary.

Painting your anchor white in med waters is an obvious starting point and takes 5 minutes a year....

 

[KellysEye]

My view was catenary holds the boat and the anchor is the back up when the wind picks up . In 15 feet of water we used 10 times depth, in 25 feet we used 7 times depth, 35 feet 5 times depth, 40 feet 3 times depth. To cut swinging we used a riding sail it cuts the swinging from up to 90 degrees to 35 degrees thereby significantly reducing snatch loads so we never dragged.

 

[geem]

My view was catenary holds the boat and the anchor is the back up when the wind picks up . In 15 feet of water we used 10 times depth, in 25 feet we used 7 times depth, 35 feet 5 times depth, 40 feet 3 times depth. To cut swinging we used a riding sail it cuts the swinging from up to 90 degrees to 35 degrees thereby significantly reducing snatch loads so we never dragged.

You would be very unpopular in most anchorages with 150 ft of chain out in 15 ft of water! We would only use half as much

 

[sarabande]

My view was catenary holds the boat and the anchor is the back up when the wind picks up . In 15 feet of water we used 10 times depth, in 25 feet we used 7 times depth, 35 feet 5 times depth, 40 feet 3 times depth. To cut swinging we used a riding sail it cuts the swinging from up to 90 degrees to 35 degrees thereby significantly reducing snatch loads so we never dragged.

150ft of chain in 15ft depth ? It looks as if you are determined to use your long chain at all depths, from the other figures.

I don't understand the physics underlying your view. Can you explain please ? And a riding V sail is useful when the wind and chain are roughly in line, but the V sail is not at all useful if the wind veers or backs 180, until the boat has reset the catenary and anchor to suit the new wind.

 

[RichardS]

150ft of chain in 15ft depth ? It looks as if you are determined to use your long chain at all depths, from the other figures.

I don't understand the physics underlying your view. Can you explain please ? And a riding V sail is useful when the wind and chain are roughly in line, but the V sail is not at all useful if the wind veers or backs 180, until the boat has reset the catenary and anchor to suit the new wind.

KellysEye theory that "the caternary holds the boat with the anchor as back up" has been joyously discussed many hundreds of times on these forums.

The conclusion arrived at during those discussions is not difficult to imagine.

Richard

 

[noelex]

My view was catenary holds the boat and the anchor is the back up when the wind picks up .

The chain is not providing much grip in this example:

 

[sarabande]

I was anchored up the R Lynher a couple of weeks back in 9ft water at low tide, with some 30ft chain out to a reversed-in Knox. Very little ebb and wind, and I could see the chain wiggling across the bottom, certainly not straight and not putting the anchor to work.

It wasn't until the ebb really started that the chain moved into a straight line catenary, and the Knox earned its money.

Sometimes a boat can be held simply by the mass of the chain (and type of bottom) but that is not a true catenary.

 

[GHA]

My view was catenary holds the boat and the anchor is the back up when the wind picks up . In 15 feet of water we used 10 times depth, in 25 feet we used 7 times depth, 35 feet 5 times depth, 40 feet 3 times depth. To cut swinging we used a riding sail it cuts the swinging from up to 90 degrees to 35 degrees thereby significantly reducing snatch loads so we never dragged.

So 150' of chain in 15 feet of water but less in 40 feet of water?

Catenary doesn't "hold" anything, it's a name used to describe a certain shape of curve.

 

[Sandyman]

The conclusion arrived at during those discussions is not difficult to imagine.

Richard

The conclusion was that it only worked on a Sunday after church in a force 4 when the sun was shining.
It was also concluded that all other conclusions were a man made myth.

Edit to add: PS this only works if you have a Knox anchor or similar.

 

[BobnLesley]

...we never dragged.

Where'd the bull go? I can only see its sh1t.

 

[Sandyman]

Need to understand what boat

 

[KellysEye]

>So 150' of chain in 15 feet of water but less in 40 feet of water?

See below it's a matter of weight the catenary in shallow water it take much longer to lift the chain the wind gets up. In deep water the catenary is much larger and thus holds the boat much longer.

>>Catenary doesn't "hold" anything, it's a name used to describe a certain shape of curve.

It's the weight of the catenary that holds the boat not the shape

 

[GHA]

>>Catenary doesn't "hold" anything, it's a name used to describe a certain shape of curve.

It's the weight of the catenary that holds the boat not the shape

You don't know the terms at all, catenary has no units, no weight, it's a description of a shape which is the result of forces, not the cause of the forces. .

There is a bit in what you say as the force to lift the last link from the seabed gets greater as the depth increases for the same scope (depth:chain length) but even then your numbers are way out. For 10mm chain with a horizontal force of 250Kg the scope required is more like 1:7.4 in 4.5m and 1:4.5 in 12.2m but even then there's little point putting all the chain out in shallower water as modern anchors can stay stuck with a few degrees of up lift from the chain. Little point unless you want to completely hack off every other boat in the anchorage by using far far too much chain.

Anyway, forget looking to catinary to reduce the dynamic loads on the anchor when the conditions really get nasty, it doesn't do much, get a proper snubber.

 

[sailaboutvic]

Where'd the bull go? I can only see its sh1t.

I wonder what I could smell

 

[Cinderella66]

PT - agree with what you say. But it is especially important to ensure that you stop yachts doing stupid things Before they do it, especially before night fall with a not so good forecast. Some times there is no alternative to the shouted "Stop", but by far the best way is to offer to help, and if its refused help them anyway if they are standing into a dangerous situation. Ask questions - like how much chain do you have - dont say you dont have enough - you will elicit the same information in the end. It is important to avoid heat - and loss of face which the French seem to suffer from by bucket loads in my humble experience! I have had few problems even from the Italians. I have suffered more damage and a refusal to talk from the French - of course with exceptions.....

My worst fear is the yacht that leaves to reset an anchor on a stern too quay, who goes forward at high speed pulling in his/her chain and then who wanders around with the anchor an unknown depth into the water effectively trawling for those chains that are set up good and tight. Especially at night..... One of those French boats in the Aegean - blue and skippered by a woman - is well worth being wary about as we had 3 attacks in 5 nights from her - despite being 6 boats away! always someone elses fault:disgust:

Why is gender relevant?

 

[RupertW]

Why is gender relevant?

I'd normally agree with you that bringing gender into a discussion isn't helpful but in this case I read it as part of describing a yacht to avoid in that cruising area - so blue, French and a female skipper. That doesn't imply to me that there is anything wrong with blue boats or French boats either but the combination of all 3 means it might be her. Perhaps the boats name would have been more conclusive.

Oh dear, I just mansplained. Sorry.

 

[Cinderella66]

Funnily enough, the issue appears to be with male skippers, statistically, there is only one identified as female, that suggests to me perhaps I should avoid all boats with male skippers as the risk of collision is greater, oh, sorry, am I being nugatory. Answers on a postcard please . . .

 

[RichardS]

Funnily enough, the issue appears to be with male skippers, statistically, there is only one identified as female, that suggests to me perhaps I should avoid all boats with male skippers as the risk of collision is greater, oh, sorry, am I being nugatory. Answers on a postcard please . . .

Nugatory ..... well that's a word I've never heard before. I live and learn.

Richard

 

[Chris_Robb]

Why is gender relevant?

Its not - thats why I wrote his/her to avoid gender specific! Although I do go on to quote a specific incident - with an "her"

 

[JanZ]

Nugatory | Definition of Nugatory by Merriam-Webster
https://www.merriam-webster.com › nug...


Nugatory, which first appeared in English in the 17th century, comes from the Latin adjective nugatorius and is ultimately a derivative of the noun nugae, meaning "trifles." Like its synonyms "vain," "idle," "empty," and "hollow," nugatory means "without worth or significance."

I learn something new every day...

Jan