|A well set anchor is a good night's sleep.|
Setting anchor under sail is a valuable skill, well documented by serious sailors in serious venues (but here you are, instead... tsk). That's easy! Most sailing is pretty easy when the sails are full.
The real challenge is not blow high, but blow low.
Wind is not always with us. The sea breeze (anabatic) tends to die just about the time we're considering calling it a day. Wind and tide don't always agree, so we're sometimes out in a flat calm riding the bus; once we've reached our stop, we still have to climb off and anchor. And the good anchorages are like little, hand-held vanity mirrors, smiling placidly up at the sunset.
There are three general ways we've settled on to get an anchor set.
In Settled Weather, when we've no expectation of change, we scull our way across our chosen spot on a heading away from any possible wind (expected, typical or geographically worst case). On command from the helm, the anchor is dropped and warp paid out slack, while the helmsperson, working the scull, huffs and puffs to a sprint. At 10:1 scope* if there's room (less if not), we make fast, charging in slow motion down the line (which is trailing over the bow and straight aft).
* NOTE: We've heard, and it seems true, that long scope allows a better set, yet retains much of its holding power when hauled in to shorter scope. Short scope will straighten chain and pull anchor sooner than long scope, but takes considerable wind to do so, even at 2:1). For setting, however, longer is better, as it helps remove spring from the line/chain.
The person at the bow keeps a hand on the line, to see if its skipping or dragging. If all goes well, though, the line goes taut and DOINKs the boat. Pretty Good Doink is the signal that we've done our worst (Anke's brother rolled it into one word, Preddygoodoink, which we've used ever since). We haul back to lesser scope, (more on this, below) and settle in for the evening. If it's a dull, draggy sludge to a halt, we pull and repeat until satisfied.
If any wind comes up, we pop out to assess our hold and take new anchor bearings. Once we've fallen back on the anchor, we jerk set to test its hold. This entails hauling sharp and fast, jerking against the inertia of the boat. It should feel hard set (no change of resistance), and the boat should accelerate toward the anchor (visible against bearings).
Sometimes, if there's a particular danger (a rock, say), we'll scull toward that. We reason that we'll want our best holding against Murphy's Wind - the one that will set us onto the worst case. If space is tight, we go as close as we dare before making fast... if the anchor doesn't set, we need room to react.
The physics of the method relies on the momentum of the boat. Even at sculling speeds of little more than a knot and a half, the momentum of a three ton boat develops high shock load (why you don't want to fend off with a leg). This buries the anchor for a decent set whenever it gets a bite.
Some anchors are better at this than others. We don't use Danforth pattern anchors for this, as they can skip at higher speeds. We want one that will sink a tooth into the bottom, and then chomp it home with the doink.
Wind Expected situations require a more secure set. We may have achieved it with the preddygoodoink, but can't test it any further than what muscle provides.
What we need is a second anchor point. This can be another anchor or a shore tie. Once this is set, we can pull on either line, which should not come home. No jumps, slides, creeps or crawls allowed.
If one of two anchors fails to set, the trick is to decide which. Careful bearings - at near right angles to the line between anchors - are the best indicator, as movement relative to them clearly shows which anchor is moving. But often, you can just feel it through the line. If the one in hand feels solid, it's likely the other that's dragging. Don't shrug it off... set and reset until everything's rock solid.
If you're feeling paranoid (and some days that's a prudent kind of a feeling), a handy billy or come-along can be used to set and test, well beyond what you can provide by hand.
Digging In by Hand is the most reliable method of all, and can be done on even the worst bottoms. We nose up to a beach or row to exposed beach. Using a WWI trenching shovel, we dig that sucker down till the shank is lying flat (can bury it, too, if that paranoid feeling is about). We've found that leaving undisturbed soil ahead of the flukes maximizes holding power, so dig a sharp wall toward the pull.
Surveying the Bottom helps a lot.
Visually, by lead or pole (which have the advantage over electronic sounders in being able to feel the bottom) , or, best of all, by foot at low tide, we gain much information seldom charted in these out-of-the-way spots.
Later, we'll draw up hand charts for the log, noting depths, patches of good holding (with bearings to find it again), foul bits to avoid and so on.
Needless to say, we hope to actually drop anchor on a good spot. As connaisseurs of bottom, we cheer for the silty suck-mud that grabs our lead in its velvet grip. Five star!
A pass or two in new territory usually turns something up. Often, once anchored, well row around prospecting spots with good protection or especially good vistas. It never hurts to row around and get an idea of the bottom around the boat's position, too... let's us know how much drag we could afford, if we did.
Over the years, our local knowledge base is growing, helping us anchor with confidence ahead of, or in the midst of bad conditions. This kind of data informs decisions on when and where to make a run for it if things take a turn for the wild side.
Nothing beats insider information!
PS. Being shoal drafted, we like the advantages of getting in close as possible. Good lees and best views of wildlife onshore. But our beaches, so close in and high up, are often cobble which resists a bite. Typically, they'll have muck at their feet, though, a bit further out.
In recent years, we've been dropping an anchor or two out in the soft bottom, with long warps in and a line to shore to limit swing and hold us close.