110 Chapter Three
The longer the rode, the more horizontal
the pull and the better the anchor
will dig in. In a storm, the longer rode helps
keep the rode horizontal at the anchor preventing
the anchor from pulling out. The
elasticity of the longer nylon rode will help
cushion the boat against wave surges.
Be sure the end of the rode is secured
to your boat! Anchors have been lost because
boaters failed to heed this simple precaution.
Anchor Line Markers
These are used to determine how much
scope has been payed (let) out. Anchor
line markers can be inserted between the
strands of a rode at regular intervals to
mark the length to that point. Some manufacturers
offer anchor line that is color
coded at various lengths.
Anchor Systems
The components of an anchoring system
are shown in Figure 10-7.
Sizing Anchor, Rope, and Chain
A typical anchor system uses nylon line
connected to chain attached to the anchor.
Obtain expert advice on the size and length
of rope and chain for your particular boat
and then experiment.
Tables of recommended anchor size
are provided by most anchor manufacturers.
They usually are based on the size of
your boat.
Tables are available, with recommendations
of rope diameter for various size
boats.
Use nylon rope of the recommended
size; oversizing will result in reduced stretch
and less shock-absorbing effect. Undersizing
may result in breakage under stress.
The length of chain is a matter of
choice, weight vs. convenience.
• At least 6 feet of chain should be used.
• A good rule of thumb is that the length
of chain should approximate the length of
the boat.
• Some boaters choose all-chain rodes.
Table 10-1. Scope vs. Conditions
Scope will vary:
• 7:1 scope is the standard for normal
conditions
• Increase to 10:1 in severe conditions
• Use a minimum of 5:1 (length = 5 x
vertical distance) for calm conditions
For example: you wish to anchor in
16 feet of water (expected depth at the
highest tide during your stay) using a
scope of 7:1; the bow of your boat is 4
feet above the surface of the water. You
will need 140 feet of rode: (16 + 4) x 7
= 140. If severe weather develops, you
would increase your scope to 10:1, using
200 feet of rode.
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60
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62
63
63A
63B
63C
anchor
Figure 10-7. Anchor system components
eye splice