Buoyage Question

[Ben44]

Hi everyone. Buoyage. I have orals shortly and could anyone help with this one.
One isolated danger mark surrounded by (for e.g.) 2 identical west cardinal marks. What does this mean and what is the significance of the 2nd cardinal? If safe water is to the west then technically if you had a west cardinal either side of an isolated danger, the buoy to the east would be incorrect (technically)? Isolated danger buoy - "isolated danger of limited extent with navigable water all around"... why would it not just have one west cardinal mark to the west of the isolated danger?

perhaps somebody should shed some light on this, this has been asked in a few orals before and some think its found more in IALA B?

[CharlieDelta]

Like this?

WC ID WC

Only time I could see that making sense is if you're facing west? Though even then it's not really correct...

[Randomist]

This is the substitute for the "New Wreak Buoy"

Two identical cardinal marks together indicate a new danger.

It is region independent and can appear in IALA A&B. My best advice to you would be to consult the admiralty publication "Guide to IALA Buoyage System" The NP number escapes me

[alistairuk]

As Randomist says, its the old / still used substitute for the "Emergency Wreck Buoy" (Which is yellow and blue) - although it's worth noting that it can be any two identical cardinals, doesn't have to be a west.

Trinity House have lots of information on the buoys they use on their web site, this particular one being located at http://www.trinityhouse.co.uk/pdfs/pdf_wreck_buoy.pdf


Other info being at; http://www.trinityhouse.co.uk/marine...ting-aids.html

[steamer]

Indeed it can also be lateral marks!!!

[Ben44]

Hello again, thanks for those answers. Makes sense. So in a buoyed channel part in Orals identify it as the emergency wreck marking buoy. Then take actions you would take on sighting it (actions the examiner wants to hear you say?), call the master, consult the chart, make a bold alteration of course around it.

Even if cardinal marks (e.g. west) are used to indicate this, do the normal principles of cardinals stop applying? i.e. you could go port/starboard if there's safe water? The trouble is having W Cardinal - Iso Danger - W Cardinal is that you might be made into thinking you HAVE to go to port (if approaching from the south), when if there's safe water u could go to starboard. See what I mean?

[alistairuk]

Do not identify it as an emergency wreck marking buoy - because it isn't - or it would be yellow and blue.

Yes, same principles apply, if it was 2 west cardinals then safe water would be to the west of the entire thing.

[Randomist]

Yeah, it's an alternative to a new wreck buoy, not the same as.

When shown this, pass to the safe water side for the cardinal type.

[Ben44]

Thanks so much for your help all.