NYC Moorings are constructed using 24mm laid polyester warp. Polyester can also be called Dacron, they are the same thing. This warp has a break load of approximately 9000 kilos (19800lbs). The warp has approximately 33% elongation (stretch) at break load, which is only a little less than nylon. Polyester has a better abrasion resistance than nylon, is the same strength as wet nylon, is not affected by most chemicals, fuels or marine growths like slime or seaweeds and is UV stable. Polyester is the same material many yachting braids are made of. The moorings are attached two, two tonne (2×2) concrete blocks, chained together by way of 2 large genuine Green shackles with safety pins (the nut and bolt type).
The shackles have a working load of 8500 kilos (18700lb) each. The break load of each shackle is 51000kilos (112200lb) so they have a very high safety margin. They attach to a large metal lug cast into the concrete block. On the bottom end of the warp is a Nylite Connector (made by Samson Ropes in the US), which is a solid round thimble which has a shroud over it to ensure there is no chafe of the warp on the block. These are real tough and used extensively in commercial marine applications. If you look closely you can see the shrouds as they are bright orange and Niue waters are clear and clean.
The concrete blocks have been placed on sand patches between the coral outcrops, to minimise environmental impact. The chances of them sliding on the seabed are very, very remote.
On the top of each mooring is a stainless steel thimble which you pass your mooring rope through and then attach the rope back to your boat. Do not pull the thimble aboard or attach it directly to your boat, the thimble is left sitting on top of the buoy in the water. The buoys float on the line so you may see the thimble move away from the buoys at times, this makes no difference to the mooring and can be expected from time to time. The buoys only hold the end of the warp up and have no structural input to the mooring. Be aware that 4 to 5 metres (13 to 16ft) below the sea surface of each mooring there are some yellow floats, the shallow moorings have 2 but some of the deeper moorings may have up to 4 of these. These floats are to help hold the warp up and off the seabed to both keep the rope safer and ensure the moorings cause the absolute minimum damage to Niues environment. The NYC prides itself on minimising its environmental impact whenever possible. One added bonus of the yellow floats is they provide extra drag through the water so help to minimise any shock loading in rougher weather. This reduces wear on the moorings and gives the attached yachts a smoother ride so one could think of them as having an additional role as shock absorbers.
The moorings vary in depth from 16 to 39 meters (52 to 128 ft). Each mooring line is equal to the water depth (from the top of the block) plus 6 metres (20 ft approx). Be aware that your boat will most likely be hanging back a little so not over the block and over a coral outcrop instead so your depth sounder may be at variance from the actual depth at the block. The NYC does have the specific depths of the blocks if you would like to know. None of the moorings are in any less than 16 metres (52ft) of water. At maximum swing any boat should not have any less than 14 metres (45ft) of clear water beneath it.
The moorings are placed in for the season (approximately 7 months of the year) then removed, cleaned, checked and stored until the following season. As an added safety measure the NYC will have its own inspection boat working during the season but if you see anything untoward at all, be it big or small, with any of the moorings please inform the NYC as soon as possible.
Information supplied by Grant Macduff, Chains, Ropes; Anchors, Auckland, NZ.