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Article
by Tor Pinney
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ANCHOR RIGHT TO STAY PUT
© 1992 Tor Pinney - All Rights Reserved
In the years I've been sailing, I've witnessed
countless anchoring antics: There was the Caribbean bare-boater who heaved
a spaghetti jumble of hook, line and chain over the bow, then jumped into
the dinghy and disappeared ashore while the yacht drifted irresolutely out
to sea. And the weekend warrior who showed up in a popular Biscayne Bay
hideaway with no anchor aboard at all! It's amazing how few sailors really
know how to anchor their boats well.
Anchoring poorly endangers not only the skipper's own
boat, but every other vessel in the harbor. Even if your anchor does
usually hold, take a moment now to review these practical pointers - tips
on how to anchor under power so that, come hell or high water, your boat
will stay where you put it.
Ground tackle - anchors, chain, line and shackles -
needs to be of a size suitable to the vessel. As a rough guideline for
sailboats of moderate size and displacement, the primary bow anchor ought
to weigh at least 1-lb. per foot of length on deck. Bigger is better. One
additional anchor, made up and ready with its rode attached, should also
be carried aboard. A third, even a fourth anchor is standard equipment
aboard boats that cruise. An anchor needs to have some sturdy galvanized
chain between it and the anchor line, no less than 15 or 20 ft. Again,
more is better. Most experienced cruising sailors fit one of their bow
anchors with an all chain rode, often using a windlass with a chain gypsy
to handle it.
As you near an anchorage, check to see that the anchors
you plan to use are ready to be lowered, that the rodes will run free, and
that the bitter ends are fastened to the vessel. If you're towing a dinghy
astern shorten up on the painter enough so that it can't possibly reach
the propeller when you're backing down.
Explain to your crewmembers what's expected of them,
assigning duties and deck positions as necessary. It's a good idea to
establish a few simple hand signals (see illustrations) so that the
helmsman and the anchor handler can communicate without shouting back and
forth to each other over the whine of the wind and the engine. Depending
on who's calling the shots, the helmsman may need to communicate the
commands to "let go (or retrieve) the anchor", "feed out
more scope", and "snub or cleat off the anchor rode". The
anchor handler needs signals to request forward, neutral, and reverse
gears, as well as higher or lower Rpm's. One husband-wife team I know even
has a signal for "calm down, dear!"

Once inside the harbor, you'll first want to consider
how the boats already there are anchored. Typically, many boats will be
swinging to a single anchor rode. But some or all of the boats may have
two anchors set off the bow, or one off the bow and one set astern. Some
may be riding on permanent moorings. When the wind or current shifts, the
vessel with two bow anchors set will swing in a shorter radius than boats
on a single anchor. Vessels anchored fore and aft won't swing at all.
Those on permanent moorings will pivot around their bows, but move very
little. In very light airs, boats with all chain rodes may not swing as
far nor as quickly as those riding to a mostly nylon rode. You, as the
newest arrival, must anchor to keep clear of vessels already there,
positioning your boat and your anchors to allow for any change in wind
direction and strength. This often means imitating the anchor arrangement
of your neighbors, or else keeping far enough away to allow room for a
different anchor plan. Bear this in mind when you select your place among
the fleet. It's always safer to leave extra space around your boat.
Now, position your boat bow to the wind (or the
current, if that's the stronger force), right about where you want to end
up once you're anchored, roughly equidistant from your nearest neighbors.
Check the depth to be sure you'll have ample water beneath you at dead low
tide. Next, motor slowly ahead a distance of about 7-times the water depth
reading you just took. Here, take a new depth sounding, and then add to
that the anticipated rise to full high tide. Use this new number to
calculate how much scope you'll be using:
A safe minimum anchor rode length in normal weather
conditions is a 7 to 1 (rode length to depth) ratio, or 5 to 1 for an all
chain rode. "Depth" in this case is the actual depth of the
water at high tide, plus the height of the anchor hawser above the water's
surface. (Scope = [water depth + hawser height] X 7). So if high water is
20 ft. deep, and your bow roller is 5 ft. above the water, you'll need to
use at least 175 ft. (25 ft. X 7) of line-plus-chain anchor rode to
anchor. It's a good idea to have your anchor rodes marked off in ten- or
twenty-foot increments to facilitate reading rode length as you feed it
out. If you anticipate a blow, a ten to one scope isn't too much to pay
out. To the extent that harbor space permits, the heavy weather rule is
the more scope the better! Remember that putting out too little scope is
one of the most common mistakes skippers make when anchoring. Later, they
wonder why their boat dragged up onto a lee shore during a squall!
While still hovering above the spot where you intend to
lower the anchor, take another look around your boat. Don't set your
anchor close alongside or close off the bows of another vessel. If you do
and the wind shifts, you may well swing into him, or he into you. In
either case, you'll be responsible for any damage caused, being the last
to have anchored. It is usually safe, however, to set an anchor close
astern of another boat, or close off his quarter. Look, also, at where the
rodes of nearby boats are pointing. A boat may have a second anchor set
off in your direction, which you could foul if you drop yours on top. If
the harbor winds are very light and variable, don't assume that everyone's
anchor is positioned straight out in front of them. In calm conditions,
anchor rodes - especially chains - may be stretched out in any direction,
towards wherever the last real breeze blew from. If in doubt, ask any
skippers you see aboard nearby boats where their anchors lie.

If everything appears to be all right, circle back
around to your intended final resting spot and then slowly coast forward
approximately the distance of your planned scope. Here, stop the vessel
completely with a short burst of reverse power. Wait until your vessel has
lost all way, coming to a complete halt before lowering the anchor. Do not
drop the hook while the boat still has any forward way on. If you do, your
anchor chain will drag over the anchor when the boat drops back and it may
foul the anchor.
When you let go the anchor, don't allow the chain and
rode to run screaming out of the chain locker to pile on top. Rather,
lower the anchor quickly but with control, paying out the rode through
gloved hands, or hand over hand, until you feel the anchor rest on the
bottom. As you begin lowering the anchor, the helmsman can shift the
engine into idle reverse, so that the vessel just begins making slight
sternway about the time the anchor reaches the bottom. (If it's windy,
leave the engine in neutral and let the boat's windage provide the backing
propulsion). As the boat continues to back slowly, feed out the anchor
rode by hand, maintaining a slight tension on it, so that it is laying out
straight on the bottom, rather than piling up. Keep the boat's reversing
speed to a bare minimum, the engine just ticking over.
Once you have fed out about one-third to one-half of
the scope with the boat still backing slowly, tighten your grip on the
rode until you feel the slack taken up and the anchor tugging. Then let
the line feed out a bit more, keeping a light tension on it so that the
anchor is being set straight. Again, tighten your grip enough to feel the
anchor tug. If your grip isn't strong enough for this, pass the line under
the horn of a deck cleat to make it easier to hold. Snub up firmly, but
not long enough to drag the anchor along on the bottom. Just long enough
to feel it tugging for a second; then ease off. Repeat this snub-and-feed
pattern several times. On a larger vessel with an all chain rode and
heavier ground tackle, it may be necessary to use the windlass gypsy for
this, alternately braking and releasing the drum.
This gentle snubbing and feeding of the rode while
backing down the boat is the surest way I know to make an anchor set, even
in difficult holding grounds. Yet it is a technique that very few sailors
seem to appreciate. It gives the anchor an opportunity to right itself,
penetrate the bottom surface, and dig in gradually. It also keeps the rode
clear of most bottom debris and it helps keep the vessel's bow from
falling off the wind. Usually, even before the scope is completely paid
out, you can feel that the anchor has set.
When you've laid out the prescribed amount of scope,
make fast the rode while the boat is still reversing at idle speed. If the
hook has taken hold, the boat will come up short on the rode and come to
an abrupt halt, firmly setting the anchor. You'll feel the vessel stop
backing and, in a moment, spring forward slightly on the rode. But there's
still one more step to being certain you're securely anchored.
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Select a range directly abeam of you, two
stationary objects, preferably ashore, which are some distance
apart but more or less lined up: a dock piling with a building
beyond; a pair of trees - whatever's handy. Now put the engine in
reverse, giving it a few hundred Rpm's above idle speed. Keeping
your eye on the range abeam, you'll see by its movement that the
boat is beginning to make sternway as the rode stretches out. If
the anchor is truly set, the boat will come to an unmistakable,
abrupt halt as soon as the rode is taught. The range points will
verify this by ceasing to move in relation to each other. Still
watching the range, increase the reverse throttle a bit more,
ensuring that the anchor will indeed hold under stress. Ease up on
the throttle and let the engine idle in reverse a moment before
shifting into neutral. This allows the anchor rode to relax
without it springing the boat forward. A cautious skipper will now
repeat this back-down maneuver at least one more time before
cutting the engine. |
If, however, the range continues to shift while you're
backing down, then the anchor is dragging. If the hook drags more than a
few yards without setting, you'll have to retrieve it and repeat the
entire anchoring sequence. In harbors with rocky or grassy beds where the
water is clear enough to see, it pays to visually locate clear patches on
the bottom into which an anchor can be lowered to set more readily. But no
matter how good your technique, some bottoms are simply poor holding and
may require repeated attempts to set a hook. Occasionally, you may bring
up the anchor to discover that it has fouled itself in an old car tire,
beach towel or paint can in which case it never would have set nor held
the boat.
In clear water where the bottom is visible, it's smart
to take a look at your anchor even after you feel it is set. Following
your own rode from the ship's bow, swim or dinghy over the anchor and look
at it through a face mask or a glass-bottom bucket. If you're a strong
swimmer, you can dive down and hand set a partially set hook by physically
jamming the point into the bottom. Afterwards, observe it from the surface
while your crew backs down with the ship's auxiliary engine. You'll see
the anchor dig itself in deeper. This is absolutely the most foolproof
method there is to ensure an anchor is set.
If, because of restricted harbor space, you have to
anchor with slightly less than optimal scope, you can enhance the holding
power of your ground tackle by weighing down the anchor rode. This calls
for a sizeable lead weight to be shackled to the rode of the anchor after
it's already set, so that the lead can slide down the line to the harbor
bottom. Tether the weight with a retrieving line so you can control how
far it travels, and so that you can pull it back up before weighing
anchor. With this lead in place on or near the harbor floor, the boat
tugging on the anchor rode must overcome and lift the weight before
putting any significant pulling force on the anchor itself. Even then, the
initial angle of pull will be more nearly horizontal, which is what you'd
have accomplished had you been able to use more scope. This technique is
no replacement for adequate scope in winds strong enough to straighten the
weighted rode, but it may be useful for a short stopover in a crowded
harbor in settled weather.
If there's a possibility of inclement weather or of a
wind shift that would swing the boat into danger, then setting a second
bow anchor is called for. Many prudent skippers always set two anchors as
a matter of course. This doesn't mean you have to get into the dinghy and
row out to windward with an anchor and a pile of chain - something I've
seen done all too often. Instead, simply determine where you want the
second anchor to be and drive the ship over there. You'll probably have to
temporarily pay out extra line on your first anchor to do this, and take
it back in once the second hook is set. Place the second anchor at an
angle of 45ø to 60ø off the first, or else in the direction of the most
likely or most threatening wind shift. Set it using the same snub-and-feed
technique described above.
Placing a stern anchor, when it's called for, can be
done by paying out and, afterwards, retrieving lots of extra bow anchor
rode, or by carrying out the stern hook in the dinghy, whichever seems
easier.
Anchoring a boat securely is among the most basic and
most important of boating skills. Learn to do it right - with technique,
control and confidence - and we'll all sleep easier in port.
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