How much stronger is an eye splice for a rope-to-chain connection on an anchor rode than a properly tied anchor bend that has a bowline on its tail secured to the standing part, around a shackle secured to the chain?
Dan Dickison responds:
Thanks for your question. John Rousmaniere addresses the issue of splicing vs. knots in his book, The Annapolis Book of Seamanship, which is a very useful tome for sailors at any level of the game. He says that "a good splice weakens a line by 10 to 15 percent, while a knot may weaken it by far more." And he does indeed recommend an eye splice be used "at the end of anchor rodes or docking lines."
Think of it this way: if a line is properly spliced, there will be almost uniform pressure on all of its strands, whereas in the case of a knot, the strands will be under an uneven load where the knot is made.
No doubt you'll find some veteran sailors who disagree with Rousmaniere's assessment. Their logic is usually based upon the notion that you can readily see anything that might go wrong with a bowline or an anchor bend, but not with a splice. Other purists hold that the shackle (which attaches the chain to the splice) is ultimately the weak link, and the spliced eye might be difficult to pass through a hawse or bow chock, so they recommend that you utilize a rope-to-chain splice. However, making rope-to-chain splices is nearly a lost technique except among traditional riggers and sailors.
Ultimately the answer to your question is a toss-up. On cruising boats, where you're apt to keep the anchor attached to the rode almost 90 percent of the time, I'm a fan of the splice approach, and I'd probably make it an eye splice so that I can detach the chain from the line should I want or need to do that. However, my approach changes for the little 15-foot runabout that I own, on board which I tie the anchor and rode together with a basic bowline capped with a half hitch in the tail. I do that because the boat is so small and we anchor it infrequently. So you can see that the decision needs to be made relative to the application you have in mind.
To have more confidence in your own splices, practice is really the only remedy. Get yourself some line to practice on and try making up a few eye splices in the evening when you've got time to sit down.