Chafe – that’s the enemy. The rope wont break, the chain wont break. The shackles wont break.

I once watched a storm front coming across Oban bay towards me. I was anchored on a lee shore.  From the dinghy I managed to get a rope round the ring in the top of a very large mooring buoy, with the anchor still down. I got the anchor up and pulled the boat up to the buoy. It was blowing F9. 10mm climbing rope didn’t break even as it was snubbing with the buoy going away as the boat lifted. I uncoupled the anchor and used the rope to pull the chain through the ring. In desperation I dropped the 6mm shackle on the end of the chain over the tee piece of the foredeck bollard, just to hold it for a few moments while I worked out something better. It didn’t even bend the pin.

The gear wont break – it’s chafe’s the problem.

Back to moorings.

 Feed a plastic tube over the pickup rope (painter). Have it long enough to go right down to the shackle. If it’s just over the stemhead it’ll do the job OK but it will work down, and it’s the very devil to stop it.

 The gear at the top of the riser can be a problem too. I like to have the swivel at the surface so that I can check it, but do you fit the buoy above or below it? Well I say on top otherwise  the  weight of the ironmongery will let it hang down beside the riser in calm conditions and possibly cause chafe. (I usually use rope for the riser)

 A word of warning about the buoy though.. It is possible for it to rub against the rope to the boat. This will become dangerous when barnacles grow on it as they will very soon damage the rope.

I like to use the big black fish farm buoys, oval with lugs at both ends. This is because you can tie on to the top lugs temporarily if you need to, which may be necessary if the pick–up has got tangled and you can’t get it aboard. (A way to avoid this is to put a long piece of tube on it as mentioned above which apart from preventing chafe, will stop it from getting wound around the riser.)

 However, unless you’re in deep water and using chain for the riser there may not be enough weight on it to keep it upright in which case the barnacles will chafe the rope.

I mentioned that I use rope for the riser. This is partly because there can be a lot of ware on the bottom link of a chain and the shackle. The size of the shackle is obviously limited by the chain size which in turn is limited by weight. If you use rope, say 30mm, then the hard eye is pretty big and you can use a big shackle.

 To my mind the advantage of rope is that there is no rust problem. The roots of the musseles will get into the rope but if you have two risers and swap them over each year when the mooring is inspected then the mussels will die off on the one that’s ashore. Just keep it out of the sun..

  If the riser is just the right length to reach the surface at high tide then it will drag on the bottom at low tide. To avoid this tie, using a rolling hitch, a trawl float about half way up the riser. If  the mooring is in shallow water try and ensure that this float is low enough not to get barnacles on it.

You really can’t avoid using shackles on the sea  bed. I wish you could. You have to rely on your diver to do them up –which is not to say that divers are unreliable, far from it, still – they have to work in difficult conditions. And the shackles MUST ALL BE MOUSED. What happens is that the rust attacks the threads so loosening them. There have been cases where the thread has disappeared altogether and it’s only the mousing that’s holding the pin in!

As long as your mooring gear is in good nick and you’ve prevented all the chafe then the boat will be OK.