Buoyage and Lights

Isolated Danger Marks

If there is a danger such as a rock or wreck that has deep water all round, it may be marked by an isolated danger marker.

An isolated Danger mark.
Isolated danger mark.

Frequently these are beacons mounted directly on to the danger.

Chart symbol

Chart symbol for an Isolated Danger buoy.


Normally a pillar buoy or, a pole beacon.


All isolated danger marks have red and black horizontal stripes with two black balls for a topmark.


The light will always be white, and have a sequence with 2 flashes. An example of an Isolated danger buoy is at (50°22'N 04°30.'W).

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