Among the most persistent falsehoods around anchoring—a subject well-known to be swimming in falsehoods, half-truths, myths, and plain old made-up bullshit—is that a kellet, i.e. a heavy lead or iron lump tied to the rode 20 to 40 feet from the anchor, somehow improves the anchor's setting and holding performance. Nobody ever proved, mathematically or empirically, that it does; someone just made up the idea and started sharing it. It found its way into some mid-20th-century books, became gospel, and even today is still presented as if it were fact by some otherwise-reputable sources.
The explanation, which probably seems quite logical to someone who's just read their first primer guide on setting and scope, is simple. If an anchor works better at 10:1 scope than at 5:1 scope, how about we tie a big weight on the rode so that the anchor "sees" a pull direction corresponding to a 10:1 scope even though the actual scope is only 5:1?
Hence, kellets. You're supposed to wrangle this 30 pound lump of iron, while dangling your arms over the bow, in close proximity to a half-deployed anchor rode that's snatching up and off tension, as the boat bucks around in the waves. Then, through the magic of 9th grade trigonometry, your anchor will set and hold in conditions where it otherwise wouldn't bite.
The sharp-eyed observer who passed 10th grade physics will of course immediately notice that, as the wind and wave forces on the boat increase, the tension on the rode increases to match. The kellet's contribution to improved scope therefore decreases. In the limit, as wind strength passes through gale force and keeps climbing, the kellet benefit drops asymptotically to near-zero.
In other words, the damn kellet just tricks you into thinking your anchor is well-set in calm conditions, and then gives up and becomes completely useless as soon as you actually need that holding power. The holding power of an anchoring system with a kellet attached actually decreases rather significantly as the loads increase.
But wait! The kellet isn't done with its antics yet. Now that the anchor which appeared to be properly set (with kellet) in calm water has broken loose, it can't reset itself. That extra "virtual scope" illusion from the kellet only worked under low tension and at low speed. Once the anchor's dragging and the boat's picking up speed astern (oh hi there, rocky shore to leeward), the kellet provides no assistance in re-setting it.
When the anchor's dragging and won't re-set, a prudent skipper fires up the engine and windlass to weigh anchor, motor out, and try again. And..... the kellet's tied to the rode. You can't get the rode back aboard until you get the kellet off. So, in weather conditions rough enough to break the anchor loose, someone has to go mess around with heavy things under tension below the bow pulpit.
"But it provides shock absorption and catenary!" the mathematically-illiterate traditionalist cries. Well, yes, it does.... as long as the wind is calm. By the time there's enough wind and waves to need that shock absorption, the rode's already pulled taut and the kellet's not helping anything.
Is there *any* case where this stupid old thing is useful? Well, yes, there is one. If:
- you are in a light wind against tide or current,
- your anchor rode has a relatively short length of chain leader,
- and you need to let out a relatively long length of rope rode to get the necessary scope,
then tying some kind of weight at the midpoint of the rode can help to prevent it from getting wrapped on the keel, prop, or rudder. But you don't need much weight for this – just a couple of pounds, to keep the rope rode down below the keel.
And, if you're the one buying the equipment, you can do a better job of solving that problem just by including a few more feet of chain leader. Or, if the boat can handle the weight, by choosing an all-chain rode.
Bottom line: In *every* possible scenario, an anchor of weight X will *always* be superior to an anchor of weight Y plus a kellet of weight Z such that X=Y+Z.
On the bright side for those of you who already have a kellet on board, the things are worth anywhere from 20 to 50 cents a pound at the scrapyard, so you might get a beer or three in exchange for one.