We bought the handheld Garmin 72 for our little 22 footer. We won't be
doing much if any long distance navigation, but just knowing our position
and just "playing" with the thing should be fun. Goofing around with it
inside (while it's cold and snowy outside) a few questions come to mind.

-- Lets say you are out in open ocean and heading for a waypoint that
it programmed into the unit. If everything was calm, no wind and no
current, all you have to do it point the arrow at the waypoint. But what
if there is a current and/or wind? Just pointing the boat toward the
waypoint might not take you on a straight course to the destination. You
would need to steer a different course to get the desired outcome. So:
Can this GPS (or others) help figure what course you need to steer?

-- I see there is a "Highway" screen that shows a "road" that one
might follow. Seems that may be the correct screen to do what I'm
thinking, but I can't quite figure out it's use.

Well, probably all this will become clearer when we can actually use
it ON the boat.

Oh, any good books out there telling how to use a GPS (not a manual
for a particual unit, but a general 'how-to' book of ideas and uses?

Thanks,
Gary

Gary Warner wrote:

We bought the handheld Garmin 72 for our little 22 footer. We won't be
doing much if any long distance navigation, but just knowing our position
and just "playing" with the thing should be fun. Goofing around with it
inside (while it's cold and snowy outside) a few questions come to mind.

-- Lets say you are out in open ocean and heading for a waypoint that
it programmed into the unit. If everything was calm, no wind and no
current, all you have to do it point the arrow at the waypoint. But what
if there is a current and/or wind? Just pointing the boat toward the
waypoint might not take you on a straight course to the destination. You
would need to steer a different course to get the desired outcome. So:
Can this GPS (or others) help figure what course you need to steer?

Certainly. The GPS unit receives frequent updates from the satellites
and knows about where you are, within a small degree of error. The
highway screen tells you whether to steer to starboard or port to reach
your destination.

However, you shouldn't overcorrect. If you are following the "highway"
function, and wind, waves and current are a factor, you will almost
always be a little off course. If you try to keep yourself centered on
the highway, you'll be doing nothing else while on your boat. Just
generally follow the highway, and make a correction every few minutes,
if need be.

-- I see there is a "Highway" screen that shows a "road" that one
might follow. Seems that may be the correct screen to do what I'm
thinking, but I can't quite figure out it's use.


Read page 19 of your manual. Garmin writes and publishes pretty decent
manuals. Those Jebbies are nothing if not well-educated.


Well, probably all this will become clearer when we can actually use
it ON the boat.

Oh, any good books out there telling how to use a GPS (not a manual
for a particual unit, but a general 'how-to' book of ideas and uses?

Thanks,
Gary


Garmin's GPS manuals contain a wealth of information about using GPS in
your life.

--
Email sent to is never read.

"Gary Warner" wrote in message
...

We bought the handheld Garmin 72 for our little 22 footer. We won't be
doing much if any long distance navigation, but just knowing our position
and just "playing" with the thing should be fun. Goofing around with it
inside (while it's cold and snowy outside) a few questions come to mind.

-- Lets say you are out in open ocean and heading for a waypoint that
it programmed into the unit. If everything was calm, no wind and no
current, all you have to do it point the arrow at the waypoint. But what
if there is a current and/or wind? Just pointing the boat toward the
waypoint might not take you on a straight course to the destination. You
would need to steer a different course to get the desired outcome. So:
Can this GPS (or others) help figure what course you need to steer?

-- I see there is a "Highway" screen that shows a "road" that one
might follow. Seems that may be the correct screen to do what I'm
thinking, but I can't quite figure out it's use.

Well, probably all this will become clearer when we can actually use
it ON the boat.

Oh, any good books out there telling how to use a GPS (not a manual
for a particual unit, but a general 'how-to' book of ideas and uses?

Thanks,
Gary


As long as you're not going long distance, this really isn't a big deal.
If you do stray off course, the little arrow will always point towards
your target. I use one all the time, and find that once I reach a
destination,
my "bread crumb" trail will be a bit curved from point A to B.

When underway,
I usually just hit the gas and check the little arrow every few minutes
to make sure Im ok.
I also have a Loran that I almost never monitor anymore and am thinking
of selling it, but a quick check on Ebay reveals these things won't fetch
much any more.

Once you use it on the water, you'll wonder how you ever got along
without it.


db

p.s. Always keep a couple packs of AA batt's on board.

Or, better yet, a 12V adapter.

D0N ßailey wrote:


p.s. Always keep a couple packs of AA batt's on board.

On Mon, 19 Jan 2004 17:40:49 -0500, Gene Kearns
wrote:

Considering that there will most assuredly be some sort of outside
influence working on your desired track, the 270 given by the GPS, you
might be forced to *steer* (by compass heading) a different number,
say 260 or 280. Your boat will crab into the wind/current much the
same way some dogs seem to run sideways.... but the *path* of your
vessel should be the 270 degrees.
============================================

Here's how I do it for what it's worth.

1. Observe course to waypoint on GPS. (Waypoint Bearing)

2. Steer same course on compass and observe Course Over Ground (COG),
or Course Made Good (CMG) for a short time (maybe 30 seconds).

3. Adjust compass course until COG/CMG equals waypoint bearing.

4. At this point the boat should be traveling in the right direction
to go directly to the waypoint with all necessary corrections built in
for current, compass error, wind, etc.

5. Re-check COG/CMG vs Waypoint Bearing periodically and adjust
compass course as required.

There are other perfectly valid techniques of course, such as setting
a "from and to" route and observing cross track error. This is
basically what the "highway" display is doing in graphical form.

Another approach which I sometimes use with my computerized charting
software, is to lay out the entire route the night before. This
creates course lines on the mapping display and you can watch the boat
move along the course out of the corner of your eye, making steering
corrections as needed. After you've found the rignt compass heading
to maintain the course, you just need to double check progress every
minute or so.

On Mon, 19 Jan 2004 18:01:18 -0500, "D0N ßailey"
wrote:
Once you use it on the water, you'll wonder how you ever got along
without it.

=====================================

It always astounds me to think that as recently as 10 or 15 years ago
we used to go all day and sometimes more without knowing exactly where
we were.

"D0N ßailey" wrote:


As long as you're not going long distance, this really isn't a big deal.
If you do stray off course, the little arrow will always point towards
your target. I use one all the time, and find that once I reach a
destination, my "bread crumb" trail will be a bit curved from point A to
B.


Which I assume is fine, unless that curved course is too big. In which case
you are traveling a longer distance than you need to or, much worse, getting
into an area of the water that you don't want to be in (say shallow or
such).
Yes?

But generally we'll just be going short distances so you're right,
it probably isn't a big deal. Just like to think it all through anyway.

Thanks all, makes perfect sense. Generally, steer to whatever compass
direction will make the boat actually *travel* the course that the GPS
sets out.

Harry - Yup, I agree the manual is pretty good. I just get the feeling
that there is more to be understood about ways to be using this
device than are in this 60 page manual. ~ This highway question
is a good example: Page 19 tells me exactly what I need to do. But
it didn't explain the currents/cross winds question.

Ok, thanks again.
Gary

Just keep the triangle pointing up.
Bill

"Gary Warner" wrote in message
...

"D0N ßailey" wrote:


As long as you're not going long distance, this really isn't a big deal.
If you do stray off course, the little arrow will always point towards
your target. I use one all the time, and find that once I reach a
destination, my "bread crumb" trail will be a bit curved from point A to
B.


Which I assume is fine, unless that curved course is too big. In which
case
you are traveling a longer distance than you need to or, much worse,
getting
into an area of the water that you don't want to be in (say shallow or
such).
Yes?

But generally we'll just be going short distances so you're right,
it probably isn't a big deal. Just like to think it all through anyway.

On Mon, 19 Jan 2004 21:00:01 -0500, Gene Kearns
wrote:

Hmmm..... I have some PFC pipe, a can of Life Guard, and a
potato...... EUREKA.....

============================

I think I hear cannon fire in the distance...