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post #11 of 25 Old 03-05-2019
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Re: Lateral Marks

With a chartplotter this becomes moot. Look at the plotter... see your boat... look at your course / heading line... are you heading toward thin water or a underwater hazard or not? It's really that simple. You don't actually need to know the color but it hopefully matches what the chart says.

Use and know how to read chart plotter and find your position and heading on it.
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post #12 of 25 Old 03-05-2019
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Re: Lateral Marks

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Originally Posted by SanderO View Post
....You don't actually need to know the color but it hopefully matches what the chart says....
I agree with your point, but this was a poor choice of words. Of course, it must match. Actually, to rely on electronic navigation, one should be actively crosschecking the match. The easiest form is to look to port or starboard, when the plotter says you should be passing an ATN and confirm its the same one in relatively the same place. Take seconds.
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post #13 of 25 Old 03-05-2019
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Re: Lateral Marks

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Originally Posted by davidpm View Post

If I'm in the fog in the LIS and see a Red mark unless I consult the chart I have no idea if I should take it on my left or right.
This is exactly the point! In unfamiliar waters, you will never know on which side to pass a mark without consulting a chart AND understanding the system by which AToNs are arranged and identified (the symbol legend for nautical charts is called "Chart no. 1" and is available here: https://nauticalcharts.noaa.gov/publ...s-chart-1.html). Simply following the marks without consulting a chart is a good way to put a hole in your boat. Is that next buoy ahead marking the channel that I'm in now or is it for an another channel, which may be on the other side of a shoal? There are only two ways to find out: consult a chart or take the risk of running your boat up on a rock.

Your friend is correct. All red and green marks are considered lateral marks (I'm assuming he meant just red and green marks and not safe water marks like red-and-white sea buoys or range marks, or hazard marks such as day beacons or lights) and the series of marks along the northern (red marks) and southern (green marks) shore of Long Island are meant to be treated like a wide channel "returning" towards the Throgs Neck.

Lateral marks may be placed near hazards but they are actually marking the lateral extent of safe water. If you don't know which side to pass on, you don't know where the safe water is. In areas like the coast of Connecticut where there are numerous ledges and many intersecting channels, it is nearly impossible to interpret which marks to follow without looking at a chart. You can tell if a lateral mark is for the Long Island sound "channel" or a smaller bay off of Long Island Sound by looking at a chart and paying attention to the numbers on the marks. Lateral marks are numbered consecutively, ascending as you progress from offshore to inshore. Greens are always odd and reds are even. So if you just passed R "2" and are now approaching R "34", you are going from one set of marks marking one channel to another set of marks delineating a different channel (or you just took a huge shortcut that will likely put you on the rocks). The intersection of the two channels may be safe or there may be a hazard present. You can't tell unless you look at a chart. The numbers on the marks are like street addresses, showing you exactly where you are (if you have looked at a chart). At night, the flashing lights serve the same purpose as the numbers during the day (the chart will say something like "Fl R 4s" which means there is a red light that flashes once every 4 seconds. Without looking at a chart, you wouldn't know what any of those flashing lights are).

A previous commenter posted about "red-right-clockwise" around a land mass; this doesn't apply to Long Island Sound. That is for the ICW. ICW marks are distinguished by the gold square (red marks) or gold triangle (green marks) at their center. Unless you see that gold shape in the center of the mark, then "red right return" still applies. Oftentimes, you can't tell whether you are departing or returning for the purposes of the AToNs unless you consult a chart.

In confined waters, the intersection of two channels is usually marked by a green-over-red or red-over-green mark; the top color marks the "preferred" route (usually the larger, deeper channel). Instead of a number, these Green-Red and Red-Green marks are usually identified by a 2-letter code that signifies local landmarks or features (e.g., "MM" for the intersection of the channels for Milton Harbor and Mamaroneck Harbor or "HL" for Hicks Ledge).

Sorry for belaboring this but if you are navigating in unfamiliar waters without consulting a chart (either an old fashioned paper one or an electronic chart), you are operating negligently. And a final note about using electronic charts: make sure you zoom-in to see the finest details. When zoomed-out, some AToNs and hazards may not be displayed on the chart (just ask the professional navigator who plowed the Vestas Wind yacht into a reef in the Indian Ocean during the Volvo Ocean Race).
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Re: Lateral Marks

Now there are some more “interesting” places where there can be a significant divergence between the chart and the chart plotter. I had one instance where I knew I was likely to have a significant chart offset. The fog was thick, but the water calm. I had maybe 60’ visability. I was trying to work into a narrow fjord like harbor on a very rocky and steep coast. On the radar I could make out the coast line but not determin with adequate certainty which indent was mine. The chart showed a sea bouy, and I could see something in the radar. But I was not positive it was my bouy, a fishing bouy, another boat, or a rock. So I proceeded gingerly until I could make it out

That allowed me to figure my true offset on the plotter and run into the harbor, very, very slowly. The plotter showed me running deep ashore through headlands. But the radar guided me.

Just a little story to say check the chart and check the mark, the kind of short cuts proposed by the Capt the OP quotes are dangerous. I suspect that gentleman was very familiar with his area, and it may coincidentally allly there. I would not try to apply it as a general rule.

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Re: Lateral Marks

Not familiar with your nav problems but on the west coast red right returns has a sub list of priority. First Facing North, Then there is Entering a port, And then there's going with the flood, and finally going upstream.. Knowing which apply to your situation may be enlightening .This system worked long before plotters but a compass is handy.
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post #16 of 25 Old 03-05-2019 Thread Starter
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Re: Lateral Marks

Thank you all and enlightening conversation.

I've got a new one for you.

You are returning to a familiar port after a huge storm.

Your channel entrance buoy is Red Nun 2 followed by 4 and 6

It is a narrow channel, it is dark and foggy with limited visibility.

As you line up for Red 2 you see that according to your chart plotter the channel is to starboard of the buoy.

You stand off a few minutes and download the notice to mariners and see no mention of the buoy being out of place but it might have moved because of the storm or the channel may have been dredged over 40 feet.

What do you do?

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post #17 of 25 Old 03-06-2019
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Re: Lateral Marks

Quote:
Originally Posted by davidpm View Post
You are returning to a familiar port after a huge storm.
...
It is a narrow channel, it is dark and foggy with limited visibility.
...
As you line up for Red 2 you see that according to your chart plotter the channel is to starboard of the buoy.
...
What do you do?
If it's a familiar port then I should already know if the charts are off or not. Firing up the radar to overlay on the chart can also verify GPS is not returning an erroneous location. That should be sufficient to confirm if the buoy is out of place. The depth finder should also help indicate if the channel itself is out of place, and you can use it to try to find known contours for additional verification.
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Re: Lateral Marks

Quote:
Originally Posted by davidpm View Post
...You stand off a few minutes and download the notice to mariners and see no mention of the buoy being out of place but it might have moved because of the storm or the channel may have been dredged over 40 feet.

What do you do?
That's Captain decision making right there. I'd be surprised that I'd download the NtMs, while standing off, but I accept that as being done in your scenario. I would then consider whether the area was prone to shoaling or whether there had been a recent severe storm. Could there be a legit reason for it to have been moved. Would continuing to take it to starboard still put me in good water, according to the charts? I would also do some sort of cross check to insure the plotter was accurately showing my location (it's already failed the reference to the AtN).

If I still question what's going on, the next step is simple. Ch16, hail the USCG and ask. They put the thing there. They'd be happy to clarify whether they moved it.


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Re: Lateral Marks

The LNM gets delivered to my inbox every Thursday. If I'm traveling, I've already reviewed it for the waters I'm navigating, and noted anything that affects my route.

If the storm happened, as you say, before the LNM was updated, (weekly) Then I'd call my Marina who would probably have the best " Local Knowledge". They will often post such anomaly's on their Facebook page, and email them to their tenants. If they have no knowledge Then, I might contact the local CG. station.

If it's dark and foggy I've fired up the Radar. My Chartplotter maintains Tracks, ( no, I don't delete them) so if it's a familiar port, I will have breadcrumbs leading me back through the route that I exited.

I doubt that the CG would have moved the Buoy and not have noted it, in their most recent LNM, So my 1st instinct would be to assume that it was off-station. However, I would make some calls, to obtain " Local Knowledge" . Then probably proceed cautiously following my tracks, radar and most importantly the depth finder.

Another option, if you're really concerned, is to drop an anchor in safe water and wait to sort things out. Wait for daylight, wait for the fog to lift, wait for information. Nothing says that you have to proceed. It's no different than heaving-to offshore, before entering an unfamiliar inlet in adverse conditions.

Several years ago, before I had radar, I left the Connecticut River headed for Block Is. Got out a mile or two into the sound and the fog was so thick you could cut it with a knife. That same morning, a ferry and a coast guard cutter collided. I turned around and followed my tracks back to the river to wait it out.
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post #20 of 25 Old 03-06-2019
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Re: Lateral Marks

Quote:
Originally Posted by davidpm View Post

You are returning to a familiar port after a huge storm.

Your channel entrance buoy is Red Nun 2 followed by 4 and 6

It is a narrow channel, it is dark and foggy with limited visibility.

As you line up for Red 2 you see that according to your chart plotter the channel is to starboard of the buoy.

You stand off a few minutes and download the notice to mariners and see no mention of the buoy being out of place but it might have moved because of the storm or the channel may have been dredged over 40 feet.

What do you do?
If it's a familiar harbor, you should have saved a route or waypoints for all of the important markers on your GPS, and you would also probably have old tracks on your GPS or plotter showing your previous transits of the channel. Lots of good advice given above (especially standing off or anchoring until the situation is sorted out and using your VHF to get local knowledge). Other good sources of local knowledge include: TowBoat/SeaTow/Vessel Assist (VHF 16). If you have the Active Captain app, you can check for comments about that channel. But take crowd-sourced information with a grain of salt. I sometimes see erroneous information posted about my local waters. And pay attention to the date of the comment if it refers to something that may change over time.
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