The emergency wreck marking buoy is used to mark newly discovered wrecks that pose a danger to navigation until a permanent solution is established.
- Colour: blue and yellow vertical stripes
- Topmark: standing/upright yellow cross
- Light: alternating blue and yellow flashing, one blue + one yellow flash per period
- Shape: pillar or spar
- RACON: Morse code "D" (dash-dot-dot)
- AIS: may be fitted with AIS transponder
This mark was introduced to provide a rapid, internationally standardized response to newly discovered dangers.
An interactive 3D illustration is shown here. The same content is described in the rule text and key takeaways below.
Buoyage Reading Order
Read the mark in a fixed order: topmark, colour pattern, light rhythm, charted meaning, then the safe side or action required.
Confirm the conventional direction of buoyage from the chart or pilotage plan before deciding port-hand or starboard-hand treatment.
Treat every mark as one aid among several.
Cross-check with charted depth, position, radar, visual bearings and the planned track.
Exam Focus
For cardinals, use the cones first, then the colour bands, then the flash mnemonic.
If those three agree, the answer is usually secure.
For lateral marks, the region only changes the colours, not the core idea: the mark still identifies the side of the channel in the conventional direction of buoyage.
Key Takeaways
Blue and yellow vertical stripes — unique colour scheme
Marks NEW wrecks not yet on charts
Alternating blue/yellow flashing light
RACON signal: Morse D
Common Mistakes
Confusing with special marks (which are all yellow)
Not giving sufficient clearance — wreck position may not be precisely charted
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