Emergency Wreck Marking Buoy

Purpose: marking a new danger

In short: a ship has just sunk where no chart shows a wreck. The emergency wreck mark goes down fast so nobody else hits it.

Read first: IALA Buoyage System and Light Characters, then Lateral Marks and Preferred Channel, Cardinal Marks, and Isolated Danger, Safe Water and Special Marks. This is the fifth and last topic of the Buoyage area.

• Purpose: marks new wrecks or hazards that are a danger to surface navigation.
• New danger (IALA R1001, 3.2.2): a newly found hazard, natural or man-made, that may not yet be shown in nautical documents and publications. It stays a “new danger” until the authority is satisfied it has been removed, or until the information has been widely promulgated.
• Where it goes: as close to the wreck as possible, or in a pattern around it (Trinity House).
• Why it exists: in the Dover Strait the car carrier Tricolor sank on 14 December 2002 after a collision. Two days later the Nicola hit the wreck. On 1 January 2003 the tanker Vicky, loaded with 77,000 t of gas oil, hit it again. IALA then created a dedicated, unmistakable mark — first IALA Recommendation O-133, now part of the Maritime Buoyage System, IALA R1001.
• Who lays it: the national authority. In the UK, Trinity House has a statutory duty to mark wrecks that are a danger to navigation (Merchant Shipping Act 1995). Costs of locating, marking and dispersing the wreck go to the ship’s insurers.

Description by day

In short: the only blue buoy in the IALA system: blue and yellow vertical stripes with an upright yellow cross.

• Colour: blue and yellow vertical stripes, equal in number and size, minimum 4 and maximum 8 stripes (IALA R1001, Table 11).
• Shape: pillar or spar. Size depends on the location.
• Topmark (if fitted): a vertical/perpendicular yellow cross — an upright “+”. IALA prefers it three-dimensional, so it looks the same from every direction.
• Memory hook: blue = brand-new. No other IALA mark uses blue.
• Trap: the special mark topmark is a yellow X (diagonal). The wreck mark topmark is a yellow + (upright).
• Both regions: identical in Region A and Region B.

Light, racon and AIS

In short: blue, yellow, blue, yellow — a light you will not see on any other mark.

• Light colour: blue and yellow, alternating, always with the same timing.
• Rhythm: 1 s blue → 0.5 s eclipse → 1 s yellow → 0.5 s eclipse (IALA R1001, Table 11). One full cycle therefore lasts 3 s.
• Nominal range: 4 NM (Trinity House).
• Several buoys round one wreck: their lights are synchronised (Trinity House).
• Racon: Morse “D” (— · ·). On the radar it paints as a dash-dot-dot line behind the buoy’s echo, on the bearing of the buoy.
• AIS: an AIS AtoN may be fitted, so the mark shows on AIS, ECDIS and radar overlays (IALA R1001, Table 11).
• On the bridge: a racon “D” or an unexpected AIS AtoN symbol is often your first warning of a new wreck, before you see the light.

How long it stays and duplicate marks

In short: it is a first-response mark. Once the wreck is charted or permanently buoyed, it goes.

• Typical time: Trinity House describes it as a temporary mark, usually for the first 24–72 h after a wreck is found.
• It stays until (Trinity House):
  • the wreck is well known and published in nautical publications;
  • the wreck has been fully surveyed, with exact position and least depth known;
  • a permanent form of marking is in place.
• Other ways to mark a new danger (IALA R1001, 3.2.2): lateral, cardinal or isolated danger marks, or the emergency wreck mark.
• Duplication: if the authority thinks the risk is especially high, at least one of the marks is duplicated.
  • The duplicate is identical to its partner in every respect.
  • A lighted lateral mark used for this shows VQ or Q.
  • It may also carry a racon Morse “D” and an AIS AtoN.

On the bridge: meeting a wreck mark

In short: treat it as an uncharted danger. Find out where the wreck is before you decide how to pass.

• Check the information: the latest navigational warnings (NAVTEX, VHF) and Notices to Mariners give the wreck position. Plot it on the chart or ECDIS.
• No safe side: unlike a cardinal, the mark does not tell you where the safe water is. A big wreck can have several buoys round it.
• Keep a wide berth, and plan your clearing distance from the wreck position, not from the buoy.
• Use every sensor: racon “D” on the radar, the AIS AtoN, and the blue/yellow light by eye.
• Do not confuse: