Pontoon
boats frequently require two anchors and two windlasses or winches. Because of
their high profile, pontoon boats tend to swing in the breeze more
than other boats. When swimming, fishing or just relaxing on the
lake or river with family and friends, two anchors keep the boat
where you want it and give you peace of mind. Two anchors will also
prevent the pontoon boat from drifting away from swimmers and into
other boats or shorelines.
Modern
anchor design and the latest engineering technology have made
anchors not only better, but also lighter in weight. In tests
conducted by the U.S. Navy, it was determined that the best holding
anchors were among some of the lightest. Anchor design rather than
weight has greater affect on holding power.
In the past
steel was commonly used in boat anchors which dramatically increased
the weight. Many materials are now stronger than steel.
Aluminum-magnesium alloy is frequently used in anchors, and is
stronger and much lighter than steel. Always set two anchors if you
expect a wind or current change.
Download
our free guide to anchoring to
find out how to anchor any boat in any conditions.
Boat Anchors and
Anchoring
Anatomy of
an Anchor
To get an idea of how each anchor type works we must know each of
its parts and functions. The shank is the stem of the anchor in
which direction is pulled to set (bury) the anchor. The crown
connects the various parts of the modern anchor. The stock turns the
anchor into an attitude that enables the flukes to dig into the sea
bed. The optional tripping ring is used for tripping with a separate
line, allowing the anchor to break out. The flukes will be buried
into the seabed. The very tip of a fluke is sometimes called the
bill.
Traditional Types of Anchor
There are six main types of anchor. They are the Fisherman, the Claw
or Bruce, the Plow or Plough, The Fluke, the Grapnel and Mushroom.
Each of these families has many anchors that relate to the basic
design principle. For example the Plow type named because it acts
like a farmers plow, has the CQR and Delta which belong to this
anchor family.
Fisherman
The fisherman is a traditional design and is often seen on the bows
of old Sailing Ships like HMS Victory. The design is a non-burying
type of marine anchor, and grabs rocks with one arm penetrating the
seabed and the other standing proud. It has a good reputation for
use in rock, kelp, and grass. However its holding power to weight
ratio is among the worst of all anchor types. The primary weakness
of the anchor design is its ability to foul the cable over changing
tides. One of the Fishermans arms can catch the anchor Rhode or
cable and accidentally trip the anchor. It is difficult to handle
and bring aboard without scarring the topsides and does not stow
well in an anchor roller.
The Fisherman is best suited for rocks, and kelp bottoms, but not
good holding in sand or mud. The Fisherman has arms which lodges
themselves in a rock bed, or as in grass and kelp, the arms allow
the anchor to penetrate through the kelp.
Modern examples of fisherman type anchors include; Luke Storm
Anchor, kedge and Navy.
Bruce/Claw
The Bruce anchor was designed by Peter Bruce back in the 1970s. The
Bruce also known as the Claw. Claw-types set quickly in most sea
beds and although not an articulated design, they have the
reputation of not breaking out with pull direction, instead slowly
turning in the bottom to align with the force. They offer a fairly
low holding power to weight ratio and generally have to be
over-sized to compete with other types. On the other hand they
perform relatively well with low rode scopes and set fairly
reliably. The traditional Claw anchor has rounded flukes. The Claw
Anchor showed poor performance in the many anchor tests, which are
attributed to the anchor failing to dig in, due to the rounded
flukes. The Rocna Spade and Supreme anchors faired much better and
many anchor tests. The Rocna Spade and Supreme anchors and are among
a new breed of anchor with roll bars and/or pointed tips.
Claw anchors are best suited for sand and muddy bottoms where the
design can dig in. Claw types boat anchors have difficulty
penetrating weedy bottoms and grass, tending to float over weed and
kelp rather than digging in.
Modern examples of claw type anchors include; Bruce, Claw, Rocna,
Spade, and Supreme
Plow or Plough
The plows holding power over a wide variety of bottom types, makes
it a top choice of cruising boaters, named for its similarity to the
farmers plow. When dropped in the water, a plow often lands on its
side. However when pulled by the ground tackle, the Plow buries
itself. Its shape allows it to reset fairly easily should the wind
or tide shift the boat position. Many manufacturers produce a
plough-style design, all based on or direct copies of the original
CQR the Coastal Quick Release. The CQR design has a hinged shank,
allowing the anchor to turn with direction changes rather than
breaking out, and also arranged to force the point of the plough
into the bottom if the anchor when it lands on its side. The more
recent Delta uses an unhinged shank and a plough with specific
angles to develop slightly superior performance. Owing to the use of
lead or other dedicated tip-weight, the plough is heavier than
average for the amount of resistance developed, and may take a
slightly longer pull to set thoroughly.
Recommended for bottom surface; Works well on many bottom surface
types. Sand, mud, and kelp grass.
Modern examples of Plow type anchors include; Delta, CQR Plow or
Plough
Fluke
The fluke style anchor, named due to its large flukes, uses a stock
at the crown to which two large flat surfaces are attached. The
stock is hinged so the flukes can orient toward the bottom (on some
designs the flukes angle can be optimized depending on the bottom
type.) The design is a burying variety, and once well set can
develop an amazing amount of resistance. Its light weight and
compact flat design make it easy to retrieve and relatively easy to
store; some anchor rollers and hawse pipes can accommodate a
fluke-style anchor. A few high-performance designs are available,
such as the Fortress, which are lighter in weight for a given area
and in tests have shown better than average results. Once set, the
fluke anchor tends to break out and reset when the direction of
force changes dramatically, such as with the changing tide, and on
some occasions it might not reset but instead drag.
The fluke is recommended for sand and muddy bottom surfaces. The
fluke anchor has difficulty penetrating kelp and weed-covered
bottoms, as well as rocky and particularly hard sand or clay
bottoms. If there is much current or the vessel is moving while
dropping the anchor it may float over the bottom due to the large
fluke area acting as a wing.
Examples of Fluke Anchor types; Fortress Danforth and Guardian
Grapnel
The grapnel style is simple to design and build. The design is a
non-burying variety, with one or more tines digging in and the
remainder above the seabed. In coral it is often able to set quickly
by hooking into the structure. A grapnel is often quite light, and
used aboard smaller boats where its weight makes it relatively easy
to bring aboard. The Grapnel is sometimes difficult to retrieve
Grapnels rarely have enough fluke area to develop much hold in sand,
clay, or mud. It is not unknown for the anchor to foul on its own
rode, like the fisherman, or to foul the tines with refuse from the
bottom, preventing it from digging in. It is quite possible for this
anchor to find such a good hook that, without a trip line, it is
impossible to retrieve.
Mushroom Anchors
Mushroom anchors work best in soft muddy bottoms, where they can
create suction which can be difficult to break. Recommended for
small boats to use as a lunch hook, but not practical for larger
boats.
Conclusion
I read somewhere a question from a new boater who asked if they
needed an anchor. The answer is yes you do its required by law in
many places and it can be one of the first pieces of emergency
equipment you'll need. Whether you sail up a river, or cross oceans
an anchor is an essential piece of gear.
When choosing which anchor is best for you, consider the important
factors are reliability to set, holding power, veering and
damage/storing. Which bottom surface do you need your anchor to work
in? How big a boat are you operating? Are you fishing or riding out
a storm?
This article will give you a guide to the various types of anchor
old and new. Which types of anchor work in which bottom surface, is
important to you. The good news is that the newer anchor technology
appears to be working and from the anchor tests we looked at the new
designs outperformed the tradition types.
In part 2 of anchoring, we provide information on ground tackle &
anchoring techniques to help you stay anchored in challenging
conditions.
About the Author
More on this and other
newsletters at http://myboatsgear.com/newsletter/200788.asp
where Mike Hobson is the editor
