Overnight Anchoring

[Dr. Hook]

Originally Posted by ShinyShoe

Because 20m of rode increases the swing diameter 40m. That reduces your choice of anchoring spot without risking swinging into others.

And if he's in a depth of 10m as suggested, does that not mean for 12:1 you are looking at 120m rather than 50m.

So you are now claiming 2 football pitch lengths of water. But how does the yacht that comes into anchor after you went ashore know you have 12:1 out. He assumes you have 6:1 to be on the safe side and drops in what he thinks is a gap. He has a keel and so experiences the tidal effect more than you so swings more quickly / less quickly depending on wind and tide.

If it needs 12:1 to be sure it will hold... I wouldn't be leaving my boat at anchor.

FFS

The 20m comment refers back to the 6:1 vs 8:1 discussion earlier.

I said 12:1 in extreme conditions.

Swing can be managed and reduced - you read my earlier remark to this effect right?



If another boat comes close to yours at anchor a) he's got a tongue in his head b) he should be able to have a stab at guessing what you might have out for the conditions forecast and keeping an appropriate distance and c) if there's any doubt that's what an anchor watch is for.

You've just miscomprehended and conflated a whole series of remarks into one just so you can disagree with me.

I think we were ALL agreed the OP's line was a bit short so can we just work together?

[Dr. Hook]

Originally Posted by Pete7

Sadly running a weight down an anchor rode to increase the catenary and therefore anchor holding doesn't work once the wind pipes up. It would be better to put the weight into a larger anchor in marginal conditions.

Scope vs catenary (Rocna Knowledge Base)



So true.

Pete

I wholeheartedly agree that a bigger digger is not to be sniffed at.


I would however say that a traveller will soak up energy in a different way to stretchy line. Nylon stretches to absorb energy. Moving a weight vertically does mechanical work (1N through 1m etc.etc.), thus absorbing energy out of a snatch. I agree that when things are really tugging it won't help the angle of lay but it will lessen the sharp tugs. It's a slightly different thing to the size of the spade but all part of a system.


The problem with discussions like these is that there are years of experience, tips and tricks to communicate. There is no one rule and everyone tries to argue about oversimplifications. Seamanship, it's all about judgement, which of course is based on..............


I'd debate the some of the Rocna article a bit over a mug of tea. The hardest bit is getting rid of the last bit of curve, which is there in their data but they kinda move on quickly. I've worked a fair bit with catenic curves in my life, from long wire survey baselines (old school), sidescan tows and multi point anchor lays.



Ahem! I note Rocna says something encouraging about 8:1.....

[Poly]

If another boat comes close to yours at anchor a) he's got a tongue in his head b) he should be able to have a stab at guessing what you might have out for the conditions forecast and keeping an appropriate distance

But I think you have overlooked the fact the OP is planning to leave a rib overnight (and presumably unmanned) and is describing a temporary mooring arrangement where he’ll likely set one length for all conditions...

...so I think you are heading towards being just as guilty of this:

You've just miscomprehended and conflated a whole series of remarks into one just so you can disagree with me.?

Nobody is leaving a rib unattended overnight in conditions where 12:1 scope would be needed unless some very bad planning has been involved.

[Dr. Hook]

I have NOT suggested a scope of 12:1 for the OP for heaven's sake!!



I don't think I'm guilty of conflating. If anything I'm trying to give general advice (post#6) which gets picked at and then everything turned into a playground fight. The OP has given very little information about their anchorage. So what has ensued is an expanding 'conversation' about anchoring in a wide variety of conditions in the absence of any other information. As such, certain advice (clearly) will not apply to this person. Certain others are getting their knickers in a twist over minutae. Perhaps I should have said 11.9:1 and everyone would be calmer.



However the 12:1 remark has got you all in a lather hasn't it. I apologise if something you haven't heard of before is impossible to get your heads round. It was a remark about a generally accepted range of scope. The only reason it emerged at all is that you quoted a manual at me in order nit pick over a small difference in range of scope. All I have sought to do is defend my remarks against other's surprise and rejection.



I think this will be my last contribution to the forum. I just want to be helpful but I can't abide middle-aged post pi**ing competitions. Enjoy yourselves. If any of the armchair salts on this website can get half as much experience as a couple of notable and gentlemanly exceptions you'll have done alright. That's the challenge though isn't it.......to talk from hard won and bitter experience.

[Poly]

Originally Posted by Dr. Hook

So what has ensued is an expanding 'conversation' about anchoring in a wide variety of conditions in the absence of any other information. As such, certain advice (clearly) will not apply to this person.

but that sort of thread drift doesn’t help the OP, if there is a genuine discussion to have about anchoring technique then start a new thread on the generality.

Perhaps I should have said 11.9:1 and everyone would be calmer.

you see - I’m sure that could be seen as being a little petty. If I somehow offended your seamanship by suggesting the >90m of rode was overkill I apologise.

However the 12:1 remark has got you all in a lather hasn't it. I apologise if something you haven't heard of before is impossible to get your heads round. It was a remark about a generally accepted range of scope.

i have heard it suggested before - although never for ribs (lower windage or just nobody would normally leave one out in such conditions?). But I agree with you if the OP had provided the detail requested in post 2 we would be better placed guide him; and of course until then I’ve been guilty of making inferences that anyone asking such a question, without any detail and proposing a <5:1 scope was not planning to be out in challenging conditions.

I think this will be my last contribution to the forum. I just want to be helpful

That is genuinely a shame if it is, because generally your posts are helpful, however if you can't accept that sometimes people will have a difference of opinion, or treat every question of anything you say as a personal affront perhaps you are not ready for the internet. For what its worth, every anchor thread I've ever read, on every forum always degenerates into a "discussion" (and I don't post on any other boating fora).