It
has been observed that unless one pays careful attention in the San
Juan Islands, after awhile all the islands begin to look alike. The
wrong turn can result in minor embarrassment, or worse, major repairs
of the boat's running gear.
So how do you keep informed of your position?
Satellites circling the earth provide a method of calculating, through
triangulation, position on the surface of our planet. While it sounds
like you'll need high school calculus, with computers to do the math
anyone who can turn on a light switch can figure out latitude and longitude,
and then simply apply this position to a chart.
In their simplest form, handheld GPSs
do just that: calculate position via triangulation based on position
of at least three satellites. More advanced units can provide the ability
to steer toward preprogrammed waypoints, and some units provide information
on the course run from point A to point B because a straight line isn't
always possible when travelling by water. The most advanced units overlay
position on an electronic version of paper charts, eliminating the need
to translate latitude and longitude into a spot on the paper chart.
Some
units provide information on the course run from point
A to point B because a straight line isn't always possible
when travelling by water.
Before discussing some of the popular GPS units on the market, we need
to make sense of some of the alphabet soup associated with them. "GPS"
of course stands for Global Positioning System. "DGPS" is
Differential Global Positioning System, a version of GPS that receives
a signal from a shore station to provide a corrected position, even
more precise. "WAAS" is the newest acronym, and stands for
Wide Area Augmentation System, which like DGPS provides more precise
positioning, but does it through land stations that broadcast position
correction information to the satellites, which then provide this information
as part of their data stream. Where GPS will get you within 49 feet
of an accurate position, DGPS can get you within nine to 15 feet, and
WAAS is supposed to provide fixes even more accurate than that.
Garmin has introduced the new GPS 72
handheld, a marine GPS that is waterproof with WAAS accuracy and, best
of all, the ability to float if dropped overboard. Great as a basic
GPS, or as a back-up to a ship-mounted system, the GPS 72 features a
120 x 160 pixel, high-contrast screen and can run up to 16 hours on
a pair of AA batteries. Providing an accurate position, as well as speed,
resetable trip timer and distance logs, the GPS 72 will also track your
course, allowing a reverse route to be run accurately. There is room
to store 500 waypoints that can be used to create up to 50 routes of
up to 50 points each. All the routes are reversible.
The GPS 72 also has alarms for anchor
drag. Built-in celestial tables suggest productive times to fish or
hunt, and list the location and time of the sun and moon risings and
settings. After an initial setup and acquisition, the unit will acquire
its position within 15 to 45 seconds. Optional data cables allow the
sharing of NMEA information or the downloading of up to one MB of data
from Garmin's MapSource CD-ROMs. With Garmin's easy-to-use interface,
this unit will become a common sight around the marina, and at a list
price of $170.65 USD (approx. $270 CDN), it should be a good seller.
Many boaters use their GPS for simple position and speed information
and have little need for advanced navigational information. For them
it may be possible to have one of their existing pieces of electronics
double up and display simple position and speed data from a black box
GPS receiver. Furuno's BBWGPS is a GPS receiver with WAAS capabilities
and contains all of the GPS electronics in the GPS antenna itself.
Providing NMEA GPS data, the BBWGPS can
be connected to many radars and other units that will display NMEA data.
Commonly used as part of Furuno's NAVnet radar chartplotters, the BBWGPS
can also be connected directly to Furuno's newest LCD fishfinder, the
LS6100. When set up this way, the LS6100 can store a dozen waypoints
and provide basic position information, as well as speed, course, waypoint
bearing and cross-track error. This data can be displayed in either
two or four user-definable data boxes, or hidden to allow full presentation
of the fishfinder data. For many freshwater anglers this may be an ideal
set-up, as they may have a need for a limited number of waypoints, and
need only the most basic GPS needs. With its six-inch Silver Brite screen,
the LS6100 is an amazing value in the low-dollar fishfinder range. The
BBWGPS receiver retails for $300 USD (approx. $466 CDN), and the LS6100
is $345 USD (approx. $536 CDN).
Many
boaters use their GPS for simple position and
speed information and have little need for
advanced navigational information.
The next step up in mounted GPS systems are dedicated receivers that
provide basic plotting information, similar to the Garmin GPS 72. Many
basic units are available from numerous manufacturers. The Furuno GP
32 is one example of a WAAS-enabled plotter. Easy to use, one-button
switches between the four display screens provide detailed information.
Waypoints are easy to enter, either when at the point or by entering
in the corresponding numeric values.
Used as a basic plotter, the GP 32 can also provide NMEA data to other
electronics. As a full-feature plotter, it allows the storing of up
to 1,000 ship's points, 999 waypoints with comments, as well as 50 routes
with up to 30 waypoints per route. Anchor alarms are augmented with
arrival, cross-track error, trip and odometer alarms. Waypoints and
routes can be uploaded and downloaded easily between the GP 32 and a
computer. With user-customizable displays, the GP 32 can be set up for
easy use by the skipper, and at a retail price of $395 USD (approx.
$614 CDN) the unit contains a lot of features.
For the mariner wanting to get the most
out of a GPS, today's full-featured chartplotters provide a visual representation
of the boat's journey over an electronic chart. Standard Horizon offers
a line of chartplotters that utilize C-Map's NT cartridges for remarkable
chart detail, as well as ease of use.
Available in black and white and colour
versions, the CP160 and CP170C (colour version) feature built-in world
maps, WAAS capability, and the ability to hold two C-Map cartridges.
With a three-year waterproof warranty, Standard is confident of their
unit's ability to withstand use in the real world, in small boats and
on flybridges. The bright colour display of the 170C is viewable in
sunlight and the menu-driven software, controlled by Standard's unique
"Shuttlepoint" system and five hot keys, makes the unit easy
to use. With 16 different icons, waypoints can be saved and easily identified
later, making the display more understandable. Additional information
can be saved with an optional C-Map data card. Data fields can be displayed
in extra large fonts, and the unit will display NMEA data from depth
sounders or other electronics.
For
the mariner wanting to get the most out of a GPS, today's full-featured
chartplotters provide a visual representation of the boat's journey
over an electronic chart.
The C-Map cartridges provide detailed information about port services
(including phone numbers) and tide information, and both the CP160 and
CP170 provide celestial information, including sunrise and set, moonrise
and set, and a calendar.
The six-inch LCD screen, coupled with
the unit's shallow depth, means that it can be mounted almost anywhere,
giving a surprisingly large display in such a small package. With 1,000
waypoints and marks of up to 10 characters, finding the right waypoint
is simple, and the programming of up to 20 routes of 30 points each
is easy. When coupled with a DSC-equipped Standard VHF, these chartplotters
can provide instant position of vessels in distress. The list price
on the CP160 is just over $1,000 USD (approx $1,555 CDN). A five-inch
version of these units (the CP150 and CP150C) is available as well,
with most of the functions, but only one C-Map card slot.
With all these GPS choices, and all so
affordable, there's almost no reason not to have the most basic equipment
onboard. Know where you are at all times. It makes it easier to return
again to the spots you enjoy, and easier to tell others where to join
you, or find you should there be trouble. It makes boating more enjoyable,
and safer. 
