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Cruising America's Great Loop and other inland routes

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Compass calculations - a little long

LG
Larry Golkin
Thu, Sep 24, 2009 1:20 PM

Friends:

What I advocate to new boaters in public boating courses is fairly straight
forward:  A GPS is functionally useless unless you can translate the position
data to a paper chart.  So, while electronics are fine, the numbers, for
example North 34 deg. 49.49 min. by West 119 def 45.45 min doesn't help you
get home or to your planned destination, unless you can place a dot on your
charts to see what these numbers mean and then plot a course from there.  This
is especially true in the fog since a GPS set to take you "home" may take you
right through an island if you don't first establish where you are on a chart
and prepare an appropriate course from there.

I have yet to have the pleasure of plotting a course from anywhere on the east
coast, but out here on the west coast, I have done plenty of long, open water
passages.  What I do is really no trick.  We have a GPS, a chart plotter, a
radar, a laptop running software, and all the other nice bells and whistles
that have taken the tedious out of navigation, but I still "fix-plot" every
hour on the hour.  To do this, I have a chart on which I have drawn my DR
plot.  Every hour I do an estimated position, and then plot the position my
GPS says.  It only takes 10 seconds and it is very easy to determine then
where you are and how the sea state is affecting your track. It is also a way
to determine if your expensive electronics are doing what they are supposed to
be doing. Then, you can make any adjustments you need to make in your
steering.  Although I use a chart plotter attached to my autopilot to track a
course, I still do fix plotting just as a back up.  Frankly, on longer open
water passages, this takes some of the monotony and boredom out of a
wheelhouse watch period, it is something to do at the moment you complete your
hourly engine room check, and is actually quite fun.  Sure it is hard to
imagine hand steering all that way, but racing sailors do it all the time, so
it is possible.  You just need to know where you are so you can determine
where you are going/need to go.

The other really nice thing about regular fix plotting is that you know where
you were within the last hour when all of your electronics (I say when, not
if) fail.  This is important so you can communicate your best estimate of your
position should it become necessary to call for assistance (assuming you have
a radio and it is working). Having at least one completely separate, hand
held, battery operated GPS is essential and enough batteries on hand to last
for the entirety of the planned trip, as well as the paper charts.  (A sextant
as a backup to the backup with knowledge how to use it also helps)

I do not see how it is possible to "miss" anywhere given the simplicity of
modern electronics coupled with some basic navigation skills, and proper
equipment/materials. I realize Bermuda is like hitting a needle in a haystack
given its size compared to the vastness of the Atlantic Ocean, but really.

Hey, for hundreds of years mariners have been hitting needles in haystacks
using little more than a compass and a chronometer.  Detailed logging is
essential on open water passages.

My wife and I will be starting our Great Loop Adventure in November of 2010
and look forward to meeting many of you folks along the way. We regularly
cruise the area in southern California between Point Conception and San Diego,
including all the offshore islands.  That stuff is easy compared to what I
perceive is the very technical nature of cruising the Loop.  We can't wait!

While I am here, can I ask a question about your anchors?  Out here, serious
cruisers are "all chain" and we carry at least two if not three anchors for
different bottom types.  We often anchor in depths greater than 30-40 feet.  I
am interested in knowing what kind of "gear" you more experienced Loopers are
using, and what you find sufficient, and necessary in terms of ground tackle.

Be well, all of you.  Be safe.  And, we'll see you all soon.

Larry
"Abreojos"
Roughwater 41
Channel Islands, California

Friends: What I advocate to new boaters in public boating courses is fairly straight forward: A GPS is functionally useless unless you can translate the position data to a paper chart. So, while electronics are fine, the numbers, for example North 34 deg. 49.49 min. by West 119 def 45.45 min doesn't help you get home or to your planned destination, unless you can place a dot on your charts to see what these numbers mean and then plot a course from there. This is especially true in the fog since a GPS set to take you "home" may take you right through an island if you don't first establish where you are on a chart and prepare an appropriate course from there. I have yet to have the pleasure of plotting a course from anywhere on the east coast, but out here on the west coast, I have done plenty of long, open water passages. What I do is really no trick. We have a GPS, a chart plotter, a radar, a laptop running software, and all the other nice bells and whistles that have taken the tedious out of navigation, but I still "fix-plot" every hour on the hour. To do this, I have a chart on which I have drawn my DR plot. Every hour I do an estimated position, and then plot the position my GPS says. It only takes 10 seconds and it is very easy to determine then where you are and how the sea state is affecting your track. It is also a way to determine if your expensive electronics are doing what they are supposed to be doing. Then, you can make any adjustments you need to make in your steering. Although I use a chart plotter attached to my autopilot to track a course, I still do fix plotting just as a back up. Frankly, on longer open water passages, this takes some of the monotony and boredom out of a wheelhouse watch period, it is something to do at the moment you complete your hourly engine room check, and is actually quite fun. Sure it is hard to imagine hand steering all that way, but racing sailors do it all the time, so it is possible. You just need to know where you are so you can determine where you are going/need to go. The other really nice thing about regular fix plotting is that you know where you were within the last hour when all of your electronics (I say when, not if) fail. This is important so you can communicate your best estimate of your position should it become necessary to call for assistance (assuming you have a radio and it is working). Having at least one completely separate, hand held, battery operated GPS is essential and enough batteries on hand to last for the entirety of the planned trip, as well as the paper charts. (A sextant as a backup to the backup with knowledge how to use it also helps) I do not see how it is possible to "miss" anywhere given the simplicity of modern electronics coupled with some basic navigation skills, and proper equipment/materials. I realize Bermuda is like hitting a needle in a haystack given its size compared to the vastness of the Atlantic Ocean, but really. Hey, for hundreds of years mariners have been hitting needles in haystacks using little more than a compass and a chronometer. Detailed logging is essential on open water passages. My wife and I will be starting our Great Loop Adventure in November of 2010 and look forward to meeting many of you folks along the way. We regularly cruise the area in southern California between Point Conception and San Diego, including all the offshore islands. That stuff is easy compared to what I perceive is the very technical nature of cruising the Loop. We can't wait! While I am here, can I ask a question about your anchors? Out here, serious cruisers are "all chain" and we carry at least two if not three anchors for different bottom types. We often anchor in depths greater than 30-40 feet. I am interested in knowing what kind of "gear" you more experienced Loopers are using, and what you find sufficient, and necessary in terms of ground tackle. Be well, all of you. Be safe. And, we'll see you all soon. Larry "Abreojos" Roughwater 41 Channel Islands, California