anchoring and marlinspike seamanship 235
to follow suit so that your boat
swings with the tide in a small
radius. Make sure when your
boat swings to a single anchor
that it clears other boats and
shoals. If you put out 250 feet of
anchor rode, then you should
expect to swing in a circle with
a 250-foot radius or 500-foot
diameter. Stay clear or upwind of
any boat that you suspect has put
out inadequate scope.- Drag indications and bearings.
Aft er you have set your anchor
(if you are doing this under power, see “Secrets to Anchoring under
Power”), and aft er the rode takes strain, check your anchor line for
dragging. Extend your arm out over the rode and place the back of your
hand on the rode. Any vibration indicates dragging. Pay some line out,
cleat it off , and repeat the drag test. Next, take a drag bearing off the beam.
Look for a natural range—it doesn’t have to be charted. Th e end of a pier
in line with a large tree can work. As long as they stay in line, you aren’t
dragging. In areas without ranges, take a bearing to a single object off the
beam. Record the bearing in your log and check it oft en. At night, use lighted
objects abeam. Anytime the wind or current causes the boat to swing, select
a new range or object abeam. As a backup, set the GPS or radar alarm to
alert you if you start to drag. Use electronics as a backup only, unless you are
in low visibility or a remote location without visual landmarks. If you start to
drag, veer (let out) scope right away.
How to Increase an Anchor’s Holding Power
In crowded anchorages, you might need to use shorter scope. Or perhaps a
blow is coming and you need to make sure your anchor stays buried. Try one
of these techniques to increase your anchor’s holding power.
Send Down a Sentinel
- Gather heavy chain, shackles, or lead weights. Place them into a canvas
or nylon bag. - Attach your largest snatch block to the rope rode so that the sheave will
ride down the rode. Attach a strong, light line, as long as your scope, to the
block.
Trip Lines
Before you lower the anchor, you might
want attach a trip line to the crown.
This marks your anchor position and
helps you retrieve a stubborn anchor.
Make the trip line longer than the
expected height of water at high
tide. Attach one end to the anchor
crown. Attach a fl oat to the other end
(a plastic jug, Styrofoam buoy ball,
or similar). Stream the trip line fi rst,
before you lower your anchor.