Clew Bay Marine Services


Mooring Notes

A mooring setup is basically a permanently installed oversized anchor and rode. The anchor itself needs to be large and heavy enough to keep it from moving. The ‘rode’ which is called the ‘riser’ or ‘mooring line’ needs to be strong and elastic to hold the boat securely and at the same time absorb the shock loads caused by the wave action. It also needs to be UV resistant, as it is constantly exposed to sunlight. The riser is connected to the boat via a pair of bridles or pennants. These too need to be strong, UV resistant and chafe resistant. Moorings can be individual systems or combined in trots.

Polypro is not as strong as nylon rope. It is also not as durable when it comes to the power washing each spring. Furthermore, polypropylene suffers badly in sunlight, losing much of its strength in as little as a year, making it problematic for longer term nautical applications such as moorings. Many of the polypropylene risers show clear signs of UV degradation after just one season.

Polypro bridle with significant chafe

Polypro riser showing UV degradation

Often coming in contact with toe rails or other seemingly smooth surfaces the bridles are subject to friction which will cause abrasion or chafe in addition to UV degradation. Without adequate chafe protection any rope can and will be worn through over time – or very quickly in storm conditions. Like the risers, the bridles are constantly exposed to sunlight and may suffer accordingy.

Mooring Upgrade Recommendations

There are several combinations of materials that can be used for mooring trots. Considering the value of an individual vessel, Clew Bay Marine Services has compiled what they feel to be a good quality setup, worthy of consideration by owners.

For the riser CBMS recommends that owners consider opting for a braided nylon rope. Nylon (polyamide) rope has good UV resistance characteristics as well as good elasticity to provide energy absorption. A braided rope has the advantage of not untwisting and then possibly hockling (or kinking) when the load is released. Most yachts would be well served by using 32mm 12 plat (braided) nylon. It is suggested that this be covered with canvas hose to protect the rope from fouling.

For the bridles CBMS recommends that owners consider using braided Spectra or Dynex. As this material is UV resistant and does not stretch it is ideally suited for mooring bridles. Not stretching eliminates a good portion of the chafe causing movement. A chafe protector, however, remains vital and must be included. The chafe protector must be securely lashed to the correct position for each individual boat.

Dynex (spectra) bridles with chafe protectors

Nylon riser with eye splice, buoy and canvas hose for fouling protection



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Clew Bay Marine Services, Ross, Kilmeena, Westport, Co. Mayo
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