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The Global Position System, (GPS), has come to the Bass angler.
This military marvel has come down in price where even the bass
fisherman can now afford one. The question seems to be, "Why
do I want one?" The answer is, "Maybe you don't."
Let's take a look at what one of these things can, and can't do,
and how to use one if you shell out the bucks.
GPS was developed for the military for field position, so each
unit could know exactly where they were without any navigation
aids, or training for that matter. The military used your tax
dollars to lauch a series of satillites all around the planet
which emit timed signals continuously. The GPS units receive this
information and calculate, (we all remember or Trigomonitry now
don't we), exactly where you are based on the know positions of
the satillites. Enough theory, the result is you can know very
acurately just where in the world you are, anytime, anyplace, any
weather, any how. Sound Great? Look a bit closer before you buy
into all of this.
Since your tax dollars paid for this thing, Congress insisted
you be able to use it. Now the military wasn't too thrilled about
the idea, but compromised with the idea of a "degraded"
mode. What this mode does, is scrabble the very exacting
information just enough where instead of getting within 10 feet,
like Uncle Sam, John Q. Public could get within, say, 100 feet.
Congress said OK but only use the scrabbler if you're off in some
conflict and it could be a matter of National Security. The
military quickly agreed and has proclaimed that we be Nationally
Secure continually since 1991. End result, don't expect to get
any closer than 100 feet to where you want to go. Bear in mind
I've spent all day very happily exploring an area 200 feet
square, or 4000 square feet. OK, so it won't get you exactly
where you want to go, but still, pretty close. Oh, and by the
way, that's 100 feet in any direction, and it changes every few
seconds. That means you can trust it to get close, just don't
count on it keeping you close.
Another little problem you should be aware of, this thing was
designed for the foot soldier. You can't walk at 60 mph, so
relative to a bass boat, this thing is slow. If you wait until
this thing says you're there, you're about 1/4 mile past it. This
also means you're likely to get pretty confused buzzing around on
a plane within 1/2 mile or so trying to steer where the unit says
to go now. Even in the fastest modes, the unit can take up to 30
seconds to figure out just were in world you are after you've
stopped. When you get close, it's idle time. You've got to slow
down to the unit's speed, because it won't speed up to yours.
One little final thing, GPS is based on what's called geodedic
coordinates, not the magnetic scale your compass uses. For the
purist, it's a difference of 7 degrees relative to earth core at
the equator. For those less technically interested, it means if
your unit says to go at 180 degrees, and you head off due south
by your compass, you're going to miss the mark by a little bit. A
detail, but sometimes an important one.
So, these things have soooo many problems they're worthless,
right? WRONG! You just have to understand how the unit works,
take advantage of the things it does well and compensate for the
rest.
Using a GPS
Regardless of the type of unit you have, (more on differences
between units later), they all will give you a direction and
distance to the place you want to go. Before we look at just how
to get there, let's take a look at just where we're trying to
get.
The most important thing you'll ever do to make getting back
to a place easy is the time you first enter in the destination in
the unit. As we saw earlier, the GPS system has a built in, (and
active), degraded mode which will introduce an error into our
location under the best of circumstances. The first trick in
using a GPS is how to reduce the error before you enter it. The
best way is also the longest and most time consuming. Throw out a
buoy and use your trolling motor the circle around it. Keep an
eye on the coordinates as you move. If you watch closely, you'll
see a pattern develope as the randomizer works in time most
noticably in the N/S coordinate. If you watch you're unit long
enough, you'll see the transition or reset of the mode which will
appear as a jump, normally North to South, of coordinates even
though you're standing still right beside the buoy. If you
remember the coordinate that's farthest off North, and the one
farthest off South, and take the average, you'll get just about
right. Same thing for East to West. How long will this take? To
really make sure you're within say 15 feet, about an hour. Is it
worth it? If you have any other way of relocating your spot, no.
Just allowing the unit to fully settle, which takes about 5
minutes for full filtering, will get you very close, say about 30
feet, or one cast. The less time you wait, the farther you'll be
off. If you were moving fast, say coming by on a plan e, you
could be off by several hundred feet, just because of the time
lag for the update rate. So, the end result is to spend a couple
of minutes for every important location before entering it in the
unit. This will pay big dividens later in trying to return to the
spot.
OK, now we have that honey hole dialed in, and we're setting a
few miles off. Just how do we get from point A to point B with
our GPS? My personal preference is to use my compass. I check the
GPS from the direction, then "steer to" with the
compass to get me off in the general direction. As I'm running,
I'll adjust course until my heading, as shown on the GPS, matches
my destination, also on my GPS. At this point, just check the
compass and fly in on instruments. You can certainly strike out
in the general direction and depend on the GPS as your sole
guide, but the update rate will lead you on a zigzag path before
you get there. This all works great for general navigation, say
running across the Big O and hitting King's Bar within a few
hundred feet. But what about finding that honey hole?
When we get within around 1/4 mile, it's time to set her down.
From this point I idle into the hole, letting my GPS catch up
with my position. My unit, like most, shows a speed over ground,
(SOG), and I'm confident in the location as soon as that reads
something I can believe, like about 4 MPH instead of 40. As the
SOG drops to range, I revert to one of my older methods to
exactly locate my hole. I either use a line up of a couple of
shore objects, if I'm in a position to see any, or I use my depth
finder. One of the beauties of the problem is that if I'm not
within shore sight, then I'm most likely on some type of
structure, a point, breakline, or something. That's about the
only reason I can think of to be looking for an exact position.
If I'm on some type of schooling pattern or such, then the
location isn't that important. If I do need exact boat position,
then the traditional ways of locating the boat over the structure
still work.
The moral of this story is a GPS will not find anything for
you that you can't somehow find now, given most cases of offshore
and near shore fishing. What it can do is save you a bunch of
time by getting you close. For long distance navigation, (what it
was designed for), the thing works like a dream. For short
distance navigation, it's helpful if you work within the limits
of the unit and have a fall back after you get near you
destination.
So, is that the whole story? Not quite. One of the more
remarkable things about computers, (and that's all a GPS is), is
they don't forget things as fishermen are prone to do. The GPS
finds a spot based on coordinates, not the 3 reeds that were set
out from the reed line year before last. So, while finding your
normal spot on your home lake may not require a GPS, finding that
spot again you did so well in the tournament 3 years ago, might.
The other thing is a GPS works the same no matter who owns or
manufactures it. This means, unlike say a LORAN unit, two people
can share GPS coordinates and find exactly the same spot, with
one never having been there. This is a major asset if you happen
to have a buddy who's home lake you're going to fish next month
and also owns a GPS. There is even a small, but growing business
of selling GPS hot spot coordinates on major lakes. A GPS may not
help you find that spot the first time, but it can sure help find
it the second time.
Going Shopping
So you've decided to take the plunge and join the GPS
revolution. What to look for? Why is that unit better than the
other?
The first thing to know about shopping for a GPS is the chip
that does all the magic for computing the location, filtering,
averaging, etc. is made, and patented by Raytheon. That means
that all GPS units compute and process the GPS information
exactly the same, regardless of price or features. Don't buy into
the fact that one unit is more precise than another, it's not.
It's all of the optional features that separate the units.
The biggest difference between the units is the viewing
screen. Since a GPS is a graphics device, the screen can make a
world of difference. The most inexpensive models have very small
screens and little extra information can be displayed. The
top-of-the-line units have large screens and can display just
about every piece of navigation information known to man, which
is to say, more than you need to know. I selected my unit, which
is a mid-priced unit, because with my failing eyesight, I could
still see the screen even at night. If you have good eyes and
want basic information, the most inexpensive units will do fine.
The biggest difference in price may be the antenna. This is a
confusing issue which costs big bucks. All units can see the
satillites with an unobstructed view, that is to say, from a bass
boat. The only reason for a separate antenna is if you want your
unit to operate with something over it's view, like from the
cockpit of a cruiser. The "handheld" units can receive
every bit as good and the permanent mounts with external antenna
for about $300 less. The extra money is for the amplifiers and
receivers to drive the weak signal from the antenna to the unit.
On the "handheld" units, the antenna is built in, so it
doesn't need all the extra circuits. Both units "hear"
the satillites roughly the same.
Now you can't get external antenna confused with a
"differential" antenna. A differential reciever gets an
extra LORAN signal from a shore source and computes extra timing
information from the satillite signal. This will make your
navigation more precise, if you have the recommended 34 foot
difference between the main antenna and the differential antenna.
Since I don't know of any 34 foot bass boats, I can't see any
advantage in a unit that is "differential ready", (they
all are since it's built into the basic GPS chip). Again for the
purist, you can divide the wavelength and place the differential
receiver at a binary length point with reduced effectiveness. My
question is, "Why?"
You'll hear alot about "routes" and
"waypoints". From our standpoint, a waypoint is a
location or spot, and a route is a line between two or more
spots. Unless you want to navigate through all of the canals on
the Butler chain without touching your unit, routes are pretty
worthless to bass fishermen. On the other hand, the more
waypoints the better. The inexpensive units store about 100
waypoints, the upper end units up to 1,000. You may find the 100
number a bit cramped after a year or two, but anything much over
200 will keep you happy for quite a while.
Speaking of waypoints, they are stored in the unit in
"static RAM". This lets the waypoint be saved even
through a change in batteries. This is not to say it is
permanent. Even the static RAM needs a occassional refresh
usually provided by the same battery as in your watch, good for
about 5 years. So, unless you want to start all over again every
few years, it's a good idea to keep a separate copy of your
waypoints. The best way is on a home computer. The designers of
the GPS thought about that and most mid to upper priced units
have an output which can be directed to a PC. By the time you buy
the unit, buy the PC adaptor, and buy the software for the
interface, writing them down by hand or just copying them in to
your PC doesn't sound too bad. It's another standard option
within the chip specification if you want it. Don't get too
excited by the standard output most mid-priced and up units have.
It's designed to interface with an autopilot on a large vessel so
you won't find much use for it right now.
One big difference to seriously consider is the naming of
waypoints. Most units allow you to enter the name of a waypoint.
Unless you're very good at remembering numbers, this is something
you will want to do. The difference between units is the number
of characters you can have in the name. Lower priced units allow
up to say 6 characters, more than a bit cryptic for a couple of
hundred waypoints. The better units will allow 12, 16 even 32
characters for a name. It doesn't sound too important now but
just wait until you try to come up with a name for the 6th point
you found today on Lake Stickapig.
Most units allow you enter the current location with the push
of a single button. This is almost mandantory if you like to
enter waypoints by just idling over them. Another way to do the
same thing is your MOB feature, standing for Man Over Board. It's
a nice feature with too many side effects in most units, so don't
spend extra money for MOB. However you enter a waypoint, make
sure your unit will allow you to name and sort them.
Everyone wants to show you their "steer to" screen,
which is nothing more than an artifical horizon view of your
course based on your destination. This is the screen everyone
starts out wanting to use, and ends up pitching in favor for
numeric position. The screen is a very nice graphic interface if
you're going very slow at a long distance, (which case we said
we'd prefer the compass since it updates faster.) For normal and
close in navigation, the update rate for the filters is too slow
to be of much use. Most of the better units have this screen,
just don't pay a bunch extra for something you'll quickly out
grow.
The one "feature" you won't leave home without is
the mounting bracket. These pieces of plastic convert your
handheld unit to a console mount. They provide for battery power,
(a must), and hold the unit on the console, for the most part.
One thing I've discovered is the mounts weren't designed for bass
boats going over 2 foot wakes. It's a good way to find you're
unit in your lap, or worst, over the side. To cure this, I added
an option, a very large rubber band from a cheap pair of goggles.
It holds my unit in place even in the roughest waves. I may still
loose electrical contact, but the unit is still on the console.
Mounting brackets are available for just about all handheld units
and come standard with the mid-price ones.
There are, of course, all sorts of other things, which are all
just bells and whistles, all of which add to the cost of the
unit. Expect to pay about $300 for the lowest cost units. Some
units can cost up to $2,000. Even if you prefer the better
screen, more waypoints, longer names, and the like, you can find
a very good unit for $500 - $700. These mid price units normally
come with the mounting bracket and 12V adaptor, which is a $60 -
$70 item on the less expensive units, so they're not that much
more expensive. Choose the unit with the features important to
you at the cost you are willing to pay.
The GPS units aren't magic, and they're not for everyone. If
you are a serious tournament angler that likes to fish deep
structure off shore, then it's a tool you need to consider. For
those who are going to make the run across the Big-O on a regular
basis, it's a piece of safety gear highly reccommended. What ever
your needs, GPS units are here to stay and are one more tool the
bass angler needs to be aware of, if only to say, "I'll wait
until the price comes down."
Paul Crawford
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