Chart Symbols

Light (lighthouse or beacon light)

A magenta flare points from the light's position. The characteristic, height and range are printed beside it, e.g. Fl(3)10s15M.

Fog signal

Magenta arcs spreading from a position. The type is written beside it: Horn, Siren, Bell, Whis.

Leading line

A firm line drawn through two leading marks, with the bearing to steer, e.g. Ldg Lts 270°. Keep the two marks in line.

Anchorage

A magenta anchor marks a recommended anchorage, often with a number for large ships.

Anchoring prohibited

An anchor struck through. Usually over cables or pipelines. The limit of the area is drawn as a magenta T-line.

Fishing prohibited

A magenta fish struck through, often found near cables, pipelines and protected areas.

Submarine cable

A wavy magenta line. Do not anchor or trawl near it.

Submarine pipeline

A dashed magenta line with small circles. Oil, gas, water or outfall pipes on the seabed.

Restricted area limit

A magenta dashed line with T marks pointing into the area. Entry or activity is restricted; the chart or a note says how.

Traffic separation scheme

Magenta tinted separation zone between two lanes, with arrows showing the direction of traffic. Cross on a heading at right angles (Rule 10).

Wreck showing hull or superstructure

A stylised hull: part of the wreck is visible at chart datum. Give it a wide berth.

Dangerous wreck, depth unknown

The wreck sign inside a dotted danger line with a blue tint: it could be a hazard to surface vessels.

Wreck not dangerous to surface navigation

The same wreck sign with no danger line or tint. Avoid anchoring or trawling over it.

Rock which covers and uncovers

An asterisk. Its drying height above chart datum is usually shown in brackets, e.g. (1₂) means 1.2 m above datum.

Rock awash at chart datum

A cross with a dot in each angle. The rock is just at the surface at chart datum.

Underwater rock, dangerous, depth unknown

A plain cross inside a dotted danger line. Depth is unknown but it is considered dangerous.

Obstruction

Obstn inside a danger line: something on the seabed that is not a rock or a wreck, depth unknown.

Overfalls, tide rips and races

Rows of short wavy lines. Steep, breaking seas where the stream runs over an uneven bottom, worst in wind against tide.

Eddies

Small curling spirals. Circular water movement, often off headlands.

Kelp, seaweed

Wavy fronds. Weed can foul propellers and make anchors drag.

Tidal stream diamond

A magenta diamond with a letter. A table on the chart gives the stream's direction and rate at that spot for each hour before and after HW at the standard port.

Flood tidal stream with rate

An arrow with half-feathers on the shaft. The rate at springs is printed beside it, e.g. 2.4kn.

Ebb tidal stream with rate

A plain arrow with no feathers. The flood arrow has feathers; the ebb does not.

Drying height

An underlined figure in a green (intertidal) area: the height above chart datum, here 2.3 m. It dries at low water.

Sounding (depth below chart datum)

A figure in sloping type: the depth below chart datum in metres, here 12.4 m. Shallow water is tinted blue.

Marina / yacht harbour

A small magenta yacht symbol.

Tower (conspicuous)

A circle with a central dot marks an exact landmark position. Conspicuous features have their name in capitals or Conspic beside them, and make good fix marks.