Guide to Using a Swinging Mooring - Chichester Harbour ...

MooringEquipmentA Conservancy maintainedmooring consists of a heavyblack iron chain riser, whichis attached to a sinker orground chain. The swivelallows the boat to swingfreely at the mooring withouttwisting or snagging themooring top chain and anyropes passed to the swivel.The length of the top chain is standardised to suit the average deck layout of atypical yacht using our moorings and is approximately 2.5m long. The length oftop chain will not suit all deck arrangements and it may need to be adjusted tosuit your individual requirement. It can be shortened by increasing the size of theend loop; or on rare occasions, lengthened by introducing an additional length tothe chain.

Considerations When Securing to a BuoyMoored boats behave in different ways; characteristics suchas hull shape and draft will affect how a boat lies at themooring during changes in the tide. Windage on sprayhoods and canvas covers, will be affected by thestrength of the wind and wind direction, which alsoplays a part in creating a unique swinging patternand how the vessel lies with neighbouring boats.Minimising the swinging circle is an importantconsideration. The length of the mooring top chainbetween the deck fairlead and the buoy should be asshort as possible. This also ensures that the weight of theboat is directly linked to the riser and limits the amount ofsnatch to the boat deck fittings.An excessively long top chain will alsocause the buoy to rub alongside thehull of the boat and scuff the gel coator varnish. This is often observed andcan be reduced by using the correctlength of top chain as previouslydescribed.Mooring SwivelIt is important that the swivel on the topof the buoy is free to rotate and that nothing is attached from the boat below thisswivel, such as a rope preventer.A rope secured directly to the buoy will quicklyfoul the swivel and cause the top chain to twistand shorten, which then hampers the freeswinging of the boat at the mooring.Any boat using a mooring must haveinsurance against third-party claims for atleast the minimum sum recommended byleading marine insurers.

Deck ArrangementsThere are many variations of deck layouts and eachwill have its own considerations when securing to aswinging mooring. The most effective arrangementis one with a bow fairlead; this enables a straightpull to a deck fairlead or Samson post. The mooringtop chain should lie on the roller with a drop nosepin or lashing above the chain to prevent the chainfrom jumping out of the fairlead. It is important thatthe pin does not interfere with the movement of thechain or take any weight.Where the top chain is fed through a fairleadmounted on the port or starboard side of the boat,the fairleads should be large enough to permit thechain to move through the fairlead and not to take the weight of the mooringdirectly.Alternatively a rope bridle attached to the mooring buoy, above the mooringswivel, could be used; the rope bridle can be adjusted so that the rope wouldtake the weight of the boat in normal conditions. It is important that the galvanisedtop chain is fitted to the boat in some manner, so that if the rope bridlefails the boat remains safely moored.Small boats that are not fitted with suitable deck arrangements to secure thebuoy top chain can secure the chain to the bow ‘D’ ring (the steel ring on thebow of the boat that isused to pull the boat onto a trailer); a stainlesssteel snap shackle fittedto the top chain isthe simplest way ofachieving this. A ropebridle can then be fittedfrom the boat to adjustand manage the safemooring of the boat tothe buoy.

PreventersSome boat owners prefer to fit a ropebridle, in addition to the top chain;this can help to minimise the weareffect that the top chain mayhave on rollers and fairleads. Aplastic tube fitted where the linepasses through thefairlead/roller, can also reducechaff. The fitting of spring or rubbersnubbers favoured by someboat owners is also an option.DroguesFor light displacement boats or boats with a highfree board, which have a tendency to ride with the wind rather than the tide, it isrecommended that a drogue be fitted at the stern of the boat. This can be aplastic bucket or canvas bag on a short length of line and will have the effect ofslowing down the rate of swing.Private MooringsAll moorings are categorised by the maximum length of vessel authorised by themooring site licence issued by the Conservancy. Whilst a mooring may be classifiedas a C3, for instance a half tide mooring for a vessel up to 9m, this is subjectto local conditions and spacing with adjacent moorings. It should be borne inmind how a boat will sit when drying and re-floating on the change of tide.NB: Details in the Conditions of Site Licence or Hire of a mooring should be readcarefully by any boat owner using a mooring with regard his own liability.The most common cause of a boat breaking awayfrom a mooring is the failure of rope bridles; theseshould be thoroughly checked at regular intervals.Deck fittings, which are subjected to high forces,should also be checked regularly.

Provisions for RoughWeatherIf the advice in this leaflet is followed a yachtwill be well prepared for rough weather.However, there are a number of additionalprecautions that should be considered;yachtsmen should be aware of the windloading effect caused by spray hoods,loose/flapping sails and the potential fordamage to equipment not securely fastened.Ideally sails, sail covers and any loose deckequipment should be removed from the boatduring the autumn and winter months. If youdo leave sails on under a sail cover, this should be securely lashed with all looseends tied. Furling headsails should be tightly stowed with the sheets wrappedaround the sail at least once and any loose ropes tied down.Boats with lifting keels on a deepwater mooring should keep their keels down.This is particularly important for light displacement yachts, which could beknocked down in strong winds.Tori ChittyShould you have any further queries about the bestway to safely moor your boat, please contact theMoorings Officer at the Harbour Office - 01243 510980Chichester Harbour ConservancyHarbour OfficeItchenorChichester PO20 7AW01243 512301harbourmaster@conservancy.co.ukwww.conservancy.co.ukAll photos: Chichester Harbour Conservancy. If you are unable to use thisleaflet, please pass it on to someone who would be interested or recycle it.Published by Chichester Harbour Conservancy 2011