Couple of thoughts on chafe.
Mooring for the weekend, while on board, is one thing. Standing on shore watching your prized yacht, with the sixteen coats of imron that you flew Halekai in to buff to perfection, horse around in six footers with 50 knots of wind, is another kettle of fish.
In my opinion, most boat chocks give more to style than function. Those so located can cruise by and observe the constrution of ship or tug-boat chocks to see the difference. Those chocks are defined by the large radius built in to the chock. Chocks for wire rope are usually roller chocks. But, through a closed chock on a ship it is impossible to acheive a lead through the chock that will result in excessive chafe. Note, I said closed chock. Most of our boat chocks are open and, as mentioned, come not with good radii, but fairly sharp edges especially at extreme leads.
I installed two roller chocks, originally intended as stern chocks, in my bows for use at mooring. The rollers are angled to one another, which i dislike, and so this is not my last iteration of the idea. But they offer me much more reduction of potential chafe. We perhaps are more concerned with chafing gear than in eliminating the more serious causes of chafe. From what I can see in the photo of Halekai's boat the chock he's led through would cause a great deal of chafe were the line tending severely downward. I cannot really see well enough to say for sure. With that boat, I'm sure he's on the case and watching quite carefully, needing little from me.
An option, when leaving the boat on the mooring untended, would be to make up wire rope pendants. These would not eliminate the mooring pendant and it's desirable stretch. They could be shackled to the pendant(s) a few feet outside the chock(s) and then shackled on deck to the line(s) securing to the deck cleat(s). Being, say three to six feet in length one could use a substantial cable and eliminate any chafe concerns. Although any deficiencies in chock design would probably be revealed by the wear pattern! I know it would be more monkeying around, but it would provide a greater sense of peace while standing on shore in the above mentioned conditions.
I am also a big believer in 8-strand dacron line, the Yale cordage i believe you are referring to above. Both dacron and 8-strand construction have superior chafe resistence. The difference in strength and stretch between dacron and nylon is not sufficient, in my opinion, to make up for the superior abrasion resistance. And laid lines are clearly inferior in chafe resistance compared to 8-strand. Years ago, I believe Pli-moor made a twelve strand that would be superior yet, but I can find no recent reference to it's use.
One of the advantages to the "stern" chocks I installed is that they are "closed" chocks with the top being gated. In my next efforts, the "gate" atop will be a roller similar to the rollers on the sides of the current chocks. There will probably be four rollers by the time I'm done monkeying around, similar to what you'd see on those wire rope chocks on a ship, or over the stern of a tug. Pretty? Probably not overly. More effective though as the larger radius will be built in.
It's my opinion that most sailboats do not come equipped very well at all for securing alongside, let alone to a mooring. The addition of a few roller fairleads could go a long way towards the proper fairleading of dock lines, also. We go to extreme lengths to get all of our sail leads adjustably perfect and give short shrift to the gear that will be securing the boat while we're gone.
Good post and comments by all.
“Scientists are people who build the Brooklyn Bridge and then buy it.”
Wm. F. Buckley, Jr.