Navigation and Seamanship

4.3.5.3. Isolated danger marks

Isolated danger marks to indicate isolated dangers or minor obstacles of limited size that have navigable water all around them.

They are black with horizontal red stripes. Distinctive double black spherical top marks one above the other and group flashing (2) white lights, serve to associate isolated marks with cardinal marks. . The light is white - a group flash light Fl(2) with two flashes in a group.

Isolated danger mark

Meaning: indicates isolated danger, a submerged object

with water all around, don't pass close.

Colour: black with one or more horizontal red bands.

Top mark: black spheres.

Light: white light showing a group of two flashes.