piloting tips and techniques 75
discuss how to determine if a current is setting your boat off its
trackline, and how to correct for that.- Plot new DRs when your speed changes. When this happens, whether
by throttle, wind, or current (or any combination of them), erase the
old DRs ahead of your current position. Th ey no longer apply. Lay
down new DRs based on your new speed.
How to Become Piloting Sequence Savvy
At all times, the nautical chart must agree with the visual picture that
surrounds you.Piloting combines three methods of finding one’s position: piloting by eye;
piloting by visual bearings on charted landforms, landmarks, or navigation
aids; and piloting by electronics. The navigator must never rely on only one
method—even in the most trying conditions. Checking one method against
another keeps your boat and crew safe. The best sequence of these methods
depends on whether you are piloting offshore, inshore, or on a coastwise
passage.
Piloting by Eye. Use two objects and observe how they appear to move
relative to one another. For instance, if steering down a channel, keep the aids
to navigation lined up evenly to the right and left. On the other hand, if you
were turning into a channel, you might use a line of aids to navigation to turn
safely into the channel. In the illustration on page 76, a sharp turn to the left
is coming up. Make your turn the moment the left side markers (the 3, 5, and
7 navaids) line up. As you make your turn, concentrate on the navaids to the
right, staying inside that line for safety. While navigating, make adjustments
for wind and current. Use piloting by eye to prevent a collision with another
boat (as discussed in detail in Chapter 7) or with a buoy, beacon, or hazard
to navigation. Observe objects ahead as well as those astern. Check abeam to
sense speed along your visual TR. Make sure your visual picture agrees with
what you see on the chart. If not, slow or stop the boat and work things out.
Piloting by Visual Bearings. Maintain a dead reckoning plot as described
above, and update the plot using bearings taken with your steering or hand
bearing compass to fi xed or fl oating navaids, charted landmarks, and land-
form tangents. (Examples of the latter could include the right-hand end of a
bold island, the left -hand extremity of a line of cliff s, etc. Any sharp break in
topography that you can view in profi le and locate unambiguously on a chart
makes a good target for a tangent bearing.)
You can also take soundings by electronic transducer or lead line, cor-
rect these for the state of tide, and compare them with charted soundings to