piloting tips and techniques 77
a landmass, but it is the primary instrument for collision avoidance, low vis-
ibility navigation, and tracking of nearby squalls and storms. GPS units and
chart plotters provide an instant and highly accurate assessment of position
and speed over ground. Integrated navigation systems include a chart plotter,
radar, and depth sounder in one unit.
PRIORITIZING PILOTING INFORMATION
BASED ON SCALE
So how does the shorthanded navigator prioritize the relevance of the piloting
information gathered by the three means? Make the decision based on the scale
of your chart or plotter display. Keep in mind that the 1:80,000 scale serves
as the baseline for all coastal piloting. Navigators switch to smaller scales for
off shore work and use larger scales for inshore work.
Q offshore: scales smaller than 1:80,000
First priority: electronic (celestial as backup)
Second priority: visual bearings (as long as practicable)
Th ird priority: eye
Q coastwise: scales close to 1:80,000
First priority: visual bearings (in good visibility)
Second priority: eye
Th ird priority: electronic (higher priority in poor visibility)
Q inshore: scales greater than 1: 80,000
First priority: eye
Second priority: electronic
Th ird priority: visual bearingsSome may question the priority of electronic over visual bearings in inshore
waters. But in the twenty-fi rst century, the inshore navigator relies heavily on
GPS, chart plotter, and radar for navigation in unfamiliar, confi ned waters. Th is
does not excuse the shorthanded crew from maintaining a dead reckoning plot or
taking bearings. Th e number one form of navigation lies in what you can see.
At all times the navigator should compare the surrounding visual picture
with the chart. Even celestial navigation fi xes can be confi rmed or contradicted
by visual means. If for any reason things look wrong, stop the boat. If necessary,
anchor. Get oriented and comfortable before proceeding.
How to Determine When You Will Make Landfall
Th ere’s nothing quite like the crisp, fresh air that accompanies the passage of a
cold front on the U.S. east coast. Th e wind shift s to the northwest, and it looks
like you can see for miles and miles. Walk down to the beach and scan that
razor-sharp horizon. How far do you think you can see: 20 miles, 15 miles?