Buoy identification - for the experts

Supertramp said:
The mark is at a crossroads of ship lanes at the entrance to Carlingford. One is the route in to Warrenpoint, the other is the route of the car ferry across the entrance to the pier at Greencastle. It is confined waters with the channels buoyed. The GRG is something like the 18th green buoy on the way in. All straightforward really though 5 knts of tide makes it more exciting and worth not straying off piste.
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Being familiar with the one outside cardiff, the carlingford one was blindingly obvious to us. We were tempted to sneak across the shallows early but prudence said we headed to the dividing mark
 
oldmanofthehills said:
Being familiar with the one outside cardiff, the carlingford one was blindingly obvious to us. We were tempted to sneak across the shallows early but prudence said we headed to the dividing mark
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The range of interpretations in this thread suggests we might not all behave the same when meeting one!

Easy enough with a pilotage plan, decent weather and crew to watch for buoys. Tired, poor light, poor weather, singlehanded and a strange buoy makes for excitement.

Either way a good plan made in advance with time taken to check buoyage and tides usually pays off.
 
Mark-1 said:
Can you point out the Arrecife one, chart here:

Navionics ChartViewer
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Yup. That's out of date, works in progress finished several years ago. The PHM to the east of the tide diamond is now rgr preferred channel to starboard for the ferry terminal.

Another reason I only ever use navionics for rough passage planning, in my opinion its a bit rubbish. Others may think differently.
 
Supertramp said:
The range of interpretations in this thread suggests we might not all behave the same when meeting one!

Easy enough with a pilotage plan, decent weather and crew to watch for buoys. Tired, poor light, poor weather, singlehanded and a strange buoy makes for excitement.

Either way a good plan made in advance with time taken to check buoyage and tides usually pays off.
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What is surprising me is that sailors on here are unable to identify basic navigation marks.
 
Supertramp said:
Easy enough with a pilotage plan, decent weather and crew to watch for buoys. Tired, poor light, poor weather, singlehanded and a strange buoy makes for excitement.
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It's also worth remembering that a preferred channel buoy is intended to present a choice to those approaching from only one of the three converging channels. If one encounters an unexpected one, there's a 1 in 3 chance of interpreting it incorrectly, and thus departing the channel entirely.
 
requiem said:
It's also worth remembering that a preferred channel buoy is intended to present a choice to those approaching from only one of the three converging channels. If one encounters an unexpected one, there's a 1 in 3 chance of interpreting it incorrectly, and thus departing the channel entirely.
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Yeah, so Nav marks without a chart don't tell you much, as we all know. The channel markers nearest to me right now sit on mud at low tide - you can't just drive an Aircraft Carrier between red and greens and assume it's all ok because you're obeying the navigation marks.
 
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Baltika_no_9 said:
I'm puzzling why two channels indicated by a preferred channel marker don't end up in the same place at some point. If that is the case then the word "preferred" is meaningless. If one channel goes to place X and the other to place Y then you take the appropriate channel. The two channels in this thread both lead to Carlingford Lough so if that is your target then it is up to you which to take, both are valid. Clearly they take different routes so if your destination is more directly reached from only one of those routes before they converge again then that's different.

I'd be happy to be shown the case where two channels marked by such a buoy do not later converge. I am not suggesting they do not exist but would welcome an example.
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Plenty of these in the Wadden Sea, where often a channel branches off a main channel to go across the sandbanks to another main channel. If you work the tides carefully you can take the shortcut without having to go outside the islands.
Interestingly in Dutch there is no ‘preferred’ channel, we use the terms ‘main’ and ‘secondary’ channel, which seems more appropriate. ‘Preferred’ channel is obviously used from the point of view of big ships.
In the picture there are two bifurcation buoys, the most northerly secondary channel leads up a cul de sac, the other branches off to the NE and leads across extensive sandbanks behind Texel and Vlieland towards Terschelling. The names on the buoys tell you which is which. The chart reveals all.

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capnsensible said:
There's loads all around the world. There's more to life than just Lake Solent and are clearly in use where harbour authorities require them.

It's better for navigators to understand how they are positioned rather than argue about something that clearly is in widespread use.,
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Define 'loads' and 'widespread'.
None, zero, nada, in Australia.
Only one in all of Chile, Banco Roepke.
Only one I have seen elswhere is Newton I.o.W. if my memory serves.
 
westhinder said:
Plenty of these in the Wadden Sea, where often a channel branches off a main channel to go across the sandbanks to another main channel. If you work the tides carefully you can take the shortcut without having to go outside the islands.
Interestingly in Dutch there is no ‘preferred’ channel, we use the terms ‘main’ and ‘secondary’ channel, which seems more appropriate. ‘Preferred’ channel is obviously used from the point of view of big ships.
In the picture there are two bifurcation buoys, the most northerly secondary channel leads up a cul de sac, the other branches off to the NE and leads across extensive sandbanks behind Texel and Vlieland towards Terschelling. The names on the buoys tell you which is which. The chart reveals all.

View attachment 169791
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Looking at that one would have thought that buoy T8-so1 was abit too far to the east (right). One would have almost have sailed past the North ( left hand) option before coming to that buoy. Also, without seeing the rest of the chart , the 2 channels seem so far apart as to not being relevant to each other. Hence, the buoy might indicate that one should go to the north of D-MZ1-B. Or is that what it is actually telling the navigator & in fact it would be better placed farther to the east?
It really seems in an odd spot considering the chart scale
 
I don't feel unduly critical of the ignorati. I'm not sure that I was aware of them when I first met them many years ago, shortly after we lost our nice black SH marks. On the other hand, their meaning should be pretty clear, even without knowing them in advance.
 
capnsensible said:
Plenty of examples being posted now.

Try just about all of Scandanavia as well.
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Scandinavia is not the world.
Some creative usage out there for sure - as in post 73 where they appear to be used as a basic traffic separation scheme to keep traffic on the correct side of a channel.
With the coming of IALA their primary purpose was to replace middle ground marks.
 
Daydream believer said:
Looking at that one would have thought that buoy T8-so1 was abit too far to the east (right). One would have almost have sailed past the North ( left hand) option before coming to that buoy. Also, without seeing the rest of the chart , the 2 channels seem so far apart as to not being relevant to each other. Hence, the buoy might indicate that one should go to the north of D-MZ1-B. Or is that what it is actually telling the navigator & in fact it would be better placed farther to the east?
It really seems in an odd spot considering the chart scale
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In the Wadden Sea buoys are constantly being moved around to reflect the changing channels and depths. Charts are not necessarily redrawn at the same time. If in doubt, follow the buoys, not the chart
 
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