Maintaining
the quality appearance and condition of your boat
How
much Anchor Rode do I need
Ground
tackle
The
typical pleasure boat anchor rode is a long length of nylon line shackled to a
short length of chain at the anchor end of the rode. The chain is there mostly
to add weight to the shank of the anchor, helping the anchor dig into the
bottom. The rope part of the rode must be nylon. Nylon line is not only strong
it is also elastic. When waves roll into an anchored boat, the nylon stretches
like long rubber band, preventing the destructive jerking that occurs with a
less stretchy rode. Both three-strand and braided nylon ropes make excellent
anchor rode. Three-strand gives greater elasticity at lower cost, but braided
nylon is more flexible, making it a better choice when the rode is fed through a
deck pipe for stowage.
Ground
tackle –
is the whole anchoring system, including anchor, chain, shackles
and line. Anchors also must have
something to attach them to the boat. This is called the anchor rode and may
consist of line, chain or a combination of both.
Anchor
Size
- the ground tackle needs to be
of a size suitable to the vessel. As a rough guideline for boats 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. 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.
Rode
– is the length of line and or chain that attaches the anchor to the boat.
Simply put, the chain lead should weigh at least as much as the anchor
whose weight it is supplementing.
Scope - the angle of the rode is
described in terms of water depth to rode length i.e. 3 to 1 means that the rode
is three times as long as the depth of the water.
Seven to one would be "more" scope or a shallower angle.
The more scope the closer the shank of the anchor is to the bottom, the
better it holds.
Powering
-
refers to a technique of freeing a stuck anchor.
Take in any extra rode you can by motoring up on the anchor and then tie
the line off on the cleat. Have your mate stand back and motor the boat past the anchor.
The boat can put considerable strain on the anchor, more than most hooks
can take so be careful.
Anchor
rode
What size
rope do you need? A good rule of thumb is 1/8" of rope diameter for every 9
feet of boat length. As example, if you have a 26-foot boat, you need 3/8"
line, but you should buy 1/2" rope for a 28-footer. To determine how long
your anchor rode should be, multiply the deepest water you expect to anchor in
by eight. If you expect to anchor in 25' of water, you need 200' of rope.
What length of chain do you need? A good rule of thumb is the length of chain lead in feet ((minimum) = (weight of anchor, lb / unit weight of chain, lb/ft) times anchor materials factor (1 for steel, 1.6 for aluminum)). As an example, for a 20H Danforth Hi-Tensile anchor with a 1/2" twisted 3-strand nylon rode, you would use at least 17' of 5/16 inch Coil chain, weighing 1.15 pounds per foot.