Attaching to the Buoys

As we all start thinking about getting our boats on the water, its a good time to think about how they get attached to the buoy. The manner in which you attach is vital to the safety of your boat, and often it represents a single-point-of-failure than can mean significant damage to your boat if it lets go. Lets look at what makes a good attachment:

1) Quality line. This ideally would be 1/2 inch or better 3-strand nylon rope, with eyes spliced, not tied to the ends. Why spliced? Because knots can come undone, and splices do not lower the holding power of the rope the way knots do. And 3-strand line, besides being designed to splice, has great abrasion resistance, and just the right amount of stretch to absorb shock. That helps save your fittings. Also, avoid poly or natural fiber rope at all cost. Poly rope rots from UV exposure, and fiber rope just rots.

2) Length. Both Chapman's Piloting and The Annapolis Guide suggest a scope of 2.5/3:1 for your line. This means that if your attach point is two feet off the water, you need 6 feet of line.

3) Attach point. Use your tow eye, or deck cleats, Deck cleats are very handy, but sometimes the height of the deck makes the scope long. If you use the tow eye, just make sure it has a backing plate behind it to handle the stress and shock. A good reason to go with your tow eye is if your deck is high and boat is long. The combination of line+boat can make for a BIG swing.

4) Chafe. ANY point that the rope can rub must be protected against chafe. This is key for lines brought on to the deck. Carefully examine how the line will pass over the deck. If your bow entry is not offering protection with rollers or the like, you should add a leather or plastic cover over the line where it passes on board. A rubbing line will fail during the course of the season.

5) Hardware, You need attach points that CANNOT open inadvertently, and should be stainless steel on the boat side, and galvanized or zinced steel on the buoy side. If you use a shackle on the buoy, make sure to wire it shut with seizeing wire.

6) Noodle. A $2.00 noodle is a great way to keep your line afloat when you are off the buoy sailing, and even better, keeps the line from wrapping around the can when you are attached. Fitting hardware too big to fit in the noodle's hole? Easy; just slice the whole thing open. Insert the line, and it will close right back up to its original shape. You DO have a rigging knife with you when you sail, right??

7) Double line. Having a safety backup line is not a bad idea, but you must not go for a 'split the load' approach. Your primary line must be sized and capable of holding your boat 100% of the time. If you do use a double line, make sure you have a good way of keeping them from wrapping. They do makes rotating buoy shackles, but Practical Sailor reports that they are the biggest cause of buoy line failure. Something to keep in mind.

8) If you have a scow, a short line is best. Not only do you not need a long line because of the very low attach point, but a short line helps keep the bow to the wind, and even more important, makes it harder for the side of the boat to lift if it does get caught sideways. Think about it; if your line length plus the buoy height is less than 1/2 your beam, it will be VERY hard for your boat to roll on its side. This will help prevent the dreaded 'turtle' on the buoy. Nothing worse than coming to the lake and finding your mast stick in the bottom!

Good buoy hygiene is good sailing, for both you and your neighbors. There is nothing worse than not trusting the buoy tackle of some 23 foot boat just to windward of yours.  And you never want to come to the lake and find your boat lashed to the sea wall. An ounce of prevention is worth a pound of cure!

Want to see more details? Read on after the break:



Here is a detailed shot of my line, which I had custom made by Hooper's. You can click on the image for a better view.

Note the quality splices on both ends holding on the locking SS clip at the bow, and the galvanized shackle on the buoy. The smooth SS clip needs no eye, but I have one on the shackle side because that is rougher. There are no chafe points, and the noodle keeps the line from wrapping around the can. I am very sure this very unlikely to ever break. I figure other parts of the the whole system would fail first, which I guess is the whole idea.


Interested in how to size your line?
Courtesy of New England Rope

Size	Weight		Tensile
	lbs/100'	g/m	lbs	kg
3/16"	1.0	14.9	1,200	545
1/4"	1.5	22.3	2,000	908
5/16"	2.5	37.2	3,000	1,362
3/8"	3.5	52.1	4,400	1,998
7/16"	5.0	74.4	5,900	2,679
1/2"	6.5	96.7	7,500	3,405
9/16"	8.2	122.0	9,400	4,268
5/8"	10.0	148.8	12,200	5,539
3/4"	13.6	202.4	16,700	7,582
7/8"	18.7	278.3	23,500	10,669
1"	26.4	392.8	29,400	13,348
1-1/8"	30.6	455.3	34,000	15,436