"Bobsprit" wrote in message

| Actually, some dumb behavior on my part. I failed to put fresh batteries
aboard
| for the the GPS and left the new power cable home. I was "spot" using the
GPS
| by Sunday and I even failed to buy batteries at port jeff!

As a friend once said... Du Du Occurs!

| Yes, the small drift was just not a factor over such a short distance. The
most
| I know about the Sound's bottom is that taking more "near coastal" tracks
can
| ease current woes. On the other hand, I was expecting wind direction
changes
| and I wanted more course options afforded by being in the center of the
sound.

This amplifies the importance of maintaining a hard plot on paper chart. How
did Suzanne derive the cross track?... by hand calc or by spot check
interpolation with the GPS? Both methods are suitable.. it's the end results
that count. You'll find that current surges are typical on raised or
suddenly shallowing seafloor topography where the current is compressed and
moves at a slightly faster rate. The reason to favour the coastal [ read
shallower] areas when combating current that is against you is that the
brunt of the current will favour the deep areas and often you can encounter
a coastal eddy that actually assists your forward motion. I would maybe have
considered shorter coastal tacks than the long ones afforded by sea room if
time was an issue and the extra work involved was not impeding your
enjoyment of the sail. You'll find that options always come at a cost and
the drift afforded by the selection of open area navigation in a current may
adversely affect your ETA.

The importance of navigation and it's application is imperative to becoming
a sailor. How fast you drive a boat is of no consequence when you don't know
where you are going or how you will get there. Keep a log of every trip...
it is a valuable resource for future excursions and illustrates a respect
and proficiency in the art of sail and seamanship.

CM

| and I wanted more course options afforded by being in the center of the
sound.

This amplifies the importance of maintaining a hard plot on paper chart. How
did Suzanne derive the cross track?... by hand calc or by spot check
interpolation with the GPS?

How does this "amplify" the importance when we were, for all intents and
purposes sailing a short line of sight course? We estimated our losses at
aprox. 90 minutes and were quite close. For a 55 mile run I don't see the need
for more than crude navigation. We know the waters.
Next Spring when we do Great Gull and Block, we'll employ a higher level to
navigate safely.
In one respect, you're correct; the practice is probably worth the effort.
Maybe when we sail to Norwalk (a very short sail) we'll plot a series of
waypoints, calculate current and play by the book for the practice.

RB

"Bobsprit" wrote in message
| How does this "amplify" the importance when we were, for all intents and
| purposes sailing a short line of sight course? We estimated our losses at
| aprox. 90 minutes and were quite close. For a 55 mile run I don't see the
need
| for more than crude navigation. We know the waters.

Must be the description of your trip that confused me...

You wrote:
"Observing the track set on the GPS, sailing on a reach, with 1.5-2.5
knots of
current against, we only deviated from our track by about a mile."

So you were on a single tack for this portion of the return trip? If you
completed several tacks ... how would you calculate the combined drift or
set for cross track error.. the changing conditions would not allow a
cumulative average unless you did the calcs on paper to derive it. Hence my
statement regarding a hard plot.

This description led me to believe that prior to the 20 mile leg you did not
have line of sight. My apologies... but it seems to read that way.

"Once 20 miles of the return trip were under the keel we could see the
Manhattan skyline and
it became a line-of-site sail, though i maintained a specific (245 If I
remember right) SW compass heading anyway."

| Next Spring when we do Great Gull and Block, we'll employ a higher level
to
| navigate safely.
| In one respect, you're correct; the practice is probably worth the effort.
| Maybe when we sail to Norwalk (a very short sail) we'll plot a series of
| waypoints, calculate current and play by the book for the practice.

I look forward to your report and the discussion it will surely generate.

CM

This description led me to believe that prior to the 20 mile leg you did not
have line of sight. My apologies... but it seems to read that way.

We did not, nor did we face the worst of the current in the first few hours,
making our course fairly "true" especially in respect to the distance involved.
By maintaining our compass heading derived from the GPS, we barely deviated at
all.

RB

"Bobsprit" wrote in message
...
| This description led me to believe that prior to the 20 mile leg you did
not
| have line of sight. My apologies... but it seems to read that way.
|
| We did not, nor did we face the worst of the current in the first few
hours,
| making our course fairly "true" especially in respect to the distance
involved.
| By maintaining our compass heading derived from the GPS, we barely
deviated at
| all.

Ah.. I see how I came to be confused since you wrote... "How does this
"amplify" the importance when we were, for all intents andpurposes sailing a
short line of sight course? "
Cross track.. or drift and set are easier to estimate on a single tack and
more readily confirmed by bearing bearing fix or in the case of limited
bearing targets.. running fixes.

How did the Compass vs. GPS bearings compare? Did the discrepancy amount to
the Variation and did you get a chance to confirm if the Deviation error
made much of a difference?

Isn't this stuff interesting.... ;-)

CM

| waypoints, calculate current and play by the book for the practice.

I look forward to your report and the discussion it will surely generate.

Indeed!

RB

Exactly -and a legal responsibility of the master...

Cheers MC

Capt. Mooron wrote:

Keep a log of every trip...
it is a valuable resource for future excursions and illustrates a respect
and proficiency in the art of sail and seamanship.

CM