Putting down your own mooring

Rope risers are now becoming more and more popular here(The Clyde) 8 plait 24mm nylon is the stuff and we expect about 5yrs min.provided the riser does not come into contact with the sea bed!

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Dave,
The thing against rope is abrasion which is what you get as the tide falls and your boat trails the rope around the sea bed in the decreasing or increasing depth of water which is why we fit a 'bouncer' or 'trailer' chain several feet more than the max height of tide
Jim

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I don't know a thing about rope moorings, but the anti-chafe hose works perfectly well for chain, in which case using rope seems a risk too far. If you visit your local fire station they will almost always be happy to give you a length of condemned fire hose that will work very well as a chafe guard. The usual full size stuff, about 6 inches when flat, is a little on the large size but they also have smaller amounts of 4 inch, which I found ideal.



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We have a mooring used 12 months of the year for our 32' yacht (5 tonnes) on the west coast of Scotland in 15 metres of water. We had it laid professionally buying the tackle ourselves. It consists of three 41 lb Danforth anchors laid in a splay on 15 m long chains to a central ring in the centre where a riser is attached to the mooring buoy. The riser consists of 5 m chain, 10 m 8 plait 24mm Octoplat, 3 m chain, a swivel and finally 2 m chain to the buoy. The 4 m tidal rise and fall is coped with by the 5 m chain at the bottom of the riser so that the Octoplat never gets abrasion from the sea bed which is sand and mud. The cost of the tackle purchased from Jimmy Green in Devon was approximately £1,000. We inspect the mooring annually with a diver and in four years there has been no wear, however the top end of the riser has to be cleaned off annually from various sea life and the swivel cleared of barnacles twice a year. Very easy, as it can be reached by pulling up the riser on to a dinghy for cleaning at low tide. There is an allowance of at least 1 m for exceptional rough weather at the highest tides in the riser length.
As the mooring officer for our area I would point out that it is worth joining a local mooring association as the Crown Estate mooring charge reduces from £65 to just £35 as a member of an association plus any membership fees charged.

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Normally Harbour Master

The HM usually has a minimum spec for mooring in his jurisdiction and if you follow that you shouldn't have problems with Insurance and also system.

I see here that someone spent a 1000 notes !!!! Blimey I could lay about 50 moorings for that !!!!

Langstone Harbour - Solent with rise fall of 4.5m average on drying mooring, HW average depth about 3.5 m ...... HM advise is :

12ft 3/4 chain shackled to 3ft diameter concrete block, about 1ft thick, other end then to swivel and next 3/8 chain of 12ft. To this you fix your riding / marker buoy and then rope strops suitable for free-board height + length to mooring point on deck.

I actually used ...... 1 inch bottom chain to the block, other end to swivel and then 3/4 chain to 3/8 top chain. The 3.8 was passed over the bow roller and then 3 rope strops used. 2 went to mooring point, 3rd went to the anchor windlass as insurance...... left with a little slack to ensure the mooring point took normal weight. YES ..... my mooring is heavy .... but better safe than sorry.

The block must be dug in ..... at least till top is level or just below surface of mud ..... the suction is then immense to hold it !!

How do you carry this lot out !? Have block placed at low water mark and have bouy attached (if mooring position is always water .... then have chains etc. all attached as well and laid out ready to hang off overside)..... as soon as you can float over it BUT NOT high water you pick up buoy and various rope strops etc. attached to block and lash to strong points either side of boat ... so that block is under the boat. lash chains etc. such that when the block is let go - chains run free and without catching ........
Let tide come in and boat will lift block and all ...... might hear a few groans here !!!
Now proceed at leisurely pace top designated spot and let her go ..... but of course first you did pay out enough chain to match water depth ? .... not much more than water depth as you don't want to cover the chain with block. (note brace yourself when realesing block ..... boat tends to 'jump')

Once block is away then pay out rest of mooring chain and make fast.

Sounds more hairy and complicated than it really is .......

I used to do this with a Snapdragon 23 triple keel sailboat and even bigger blocks than this !!

Anyway - thats my penny-worth !


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
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Very specialised location

In a tidal, deep water mooring your concrete sinker wouldn't last very long, ignoring the fact that it cannot be dug in. I have not come across the three-anchor design posted previously, but virtually every mooring on Menai Strait has two, laid up- and down-tide. Mine, originally for a 29 footer and used safely for a 34 footer, were a pair of one hundredweight Admiralty pattern with about 10 fathoms of 7/8 chain between them. Riser was 3/4 inch, again 10 fathoms I think, for which a substantial buoy was needed. The cost something like 15 years ago was 600 pounds, even using 2nd hand chain, so I can well believe 1000 pounds now.

Despite this weight and design, one or two boats drag in most seasons.

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Moorings will be very dependent upon the location about which you are speaking.

A concrete weight, the norm in non-tidal Mediterranean waters, is only sensible in mud-bottom estuaries with a fairly gentle tidal flow.

In high-tidal flow sandy estuaries you need at least two good anchors (the Spade is ideal, but most of the plough type are good) of about twice the weight recommended for your bower.

On rock bottoms, especially with fairly strong streams you'll find moorings conspicuous by their absence, but the usuals are massive 2nd hand fisherman anchors or home-made grapnels.

Whilst I understand Nigel's derision - but in the Dyfi main channel, buying in all the items as new, you'd not have much change out of £1K, the same goes for Menai.

On a Virgo Voyager I'd look at 25kg anchors at either end of 20mm chain with a 16mm riser with 2 7mm stainless traces from a 1200mm mooring buoy.

The local mooring contractor is the chap to speak to, harbourmasters are a mixed bunch some have very little practical experience.

Of course, if you fabricate the anchors yourself and buy chain direct from manufacturer you'll not need to part with much more than £250.

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Have no argument except ..

I would not advise stainless for good reason ..... galvanised is recc'd for moorings and mixing any connections across galv and stainless is not a good idea.

Second Stainless gioves no indication visually of its failure, galvanised does.


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
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Re: Rope Riser

clear plastic pip[e is common and not so bad an idea .... EXCEPT to ensure that both ends are open so that rain etc. basically washes the salt out - as salt will chafe / destroy all rope ....... despite what Marlow etc. may say.


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
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I imagine it would depend to some extent on the type of bottom but does anybody know if there is formula/rule of thumb for weight of sinker for a given weight or size of boat?

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Yes it is an interesting one - I once watched a rowing boat capsize on Windermere trying to roll a weight over the side.

<hr width=100% size=1>regards
Claymore
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Thought about that and it should work but after much discussion in committee it was thought that in a high growth area of mussell and barnacle which we are in the young ones would still infiltrate and cause abrasion against the tube.I decided to let them grow,drop the mooring to the seabed where I am reliably informed the starfish will eat last seasons mussells.Let you know in March.

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I've always been told to leave the mussels on the chain as they actually protect it from corroding. Having dived regularly on my mooring I can confirm that this does seem to work, however they do occasionally need clearing off if only to reduce the weight on the buoy and reduce the effect of the tide on the mooring.

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Re: Very specialised location

Now that is strange. I have laid plenty of tidal moorings at Hoylake, in fact there must be about half a dozen sets of mine happily sinking into the abyss.

But what is stange is in the menai you used to set your legs up and down with the current, we always set the legs across the current, so the pull was using the flex in the ground chain. Always use a swivel to your upriser, always used chain with rope strops connected to that.

Would never ever consider a full rope strop, I mean why would you?

Strange how different practices occur around the coast.

<hr width=100% size=1>Julian

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Re: Very specialised location

The many different practices seem to be due to people working out what works in their area over many generations One of the things I've learnt here is that there are many different ways of doing things, and none of them are necessarily wrong.

Before the internet,people could only exchange information by word of mouth, and practices that worked locally stayed the same. It would still be a brave person who radically changed from proven local practice in real life. Especially if they were told not to do it, and then dragging or damage occured

It would be interesting to see if see if anyone has done any research on 'best practice'?

<hr width=100% size=1>Any sufficiently advanced technology is indistinguishable from a rigged demo
 
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