Annex 1 - Guidelines for the Presentation of Navigation-Related Symbols

1 Purpose

The purpose of these Guidelines is to provide guidance on the appropriate use of navigation-related symbols to achieve a harmonized and consistent presentation.

2 Scope

The use of these Guidelines will ensure that the symbols used for the display of navigation-related information on all shipborne navigational systems and equipment are presented in a consistent and uniform manner.

3 Application

These Guidelines apply to all shipborne navigational systems and equipment. The symbols listed in the appendix should be used for the display of navigation-related information to promote consistency in the symbol presentation on navigational equipment. The symbols listed in the appendix should replace symbols which are currently contained in existing performance standards. Where a standard symbol is not available, another symbol may be used, but this symbol should not conflict with the symbols listed in the appendix.

Appendix - Navigation-Related Symbols

Table 1: Own Ship Symbols

Topic	Symbol	Description
Own ship		Double circle, located at own ship's reference position. Use of this symbol is optional, if own ship position is shown by the combination of Heading Line and Beam Line.
Own ship true scale outline		True scale outline located relative to own ship's reference position, oriented along own ship's heading. Used on small ranges/large scales.
Own ship radar antenna position		Cross, located on a true scale outline of the ship at the Physical location of the radar antenna that is the current source of displayed radar video.
Own ship heading line		Solid line thinner than the speed vector line style, drawn to the bearing ring or of fixed length, if the bearing ring is not displayed. Origin is at own ship's reference point.
Own ship beam line		Solid line of fixed length; optionally length variable by operator. Midpoint at own ship's reference point.
Own ship speed vector		Dashed line – short dashes with spaces approximately twice the line width of heading line. Time increments between the origin and endpoint may optionally be marked along the vector using short intersecting lines. To indicate Water/Ground stabilization optionally one arrowhead for water stabilization and two arrowheads for ground stabilization may be added.
Own ship path prediction		A curved vector may be provided as a path predictor.
Own ship past track		Thick line for primary source. Thin line for secondary source. Optional time marks are allowed.

Table 2: Tracked Radar Target Symbols

Topic	Symbol	Description
Tracked target including dangerous target		Solid filled or unfilled circle located at target position. The course and speed vector should be displayed as dashed line, with short dashes with spaces approximately twice the line width. Optionally, time increments, may be marked along the vector. For a "Dangerous Target", bold, red (on colour display) solid circle with course and speed vector, flashing until acknowledged.
Target in acquisition state		Circle segments in the acquired target state. For automatic acquisition, bold circle segments, flashing and red (on colour display) until acknowledged.
Lost target		Bold lines across the circle, flashing until acknowledged.
Selected target		A square indicated by its corners centred around the target symbol.
Target past positions		Dots, equally spaced by time.
Tracked reference target		Large R adjacent to designated tracked target. Multiple reference targets should be marked as R1, R2, R3, etc.
Radar test target		When an internally generated test target is enabled, it should be indicated by the presentation of the large letter "X" adjacent to the target with the basic colour used for the target symbol. In addition, a bold "X" should be shown in a conspicuous location in the operational display area.

Table 3: AIS Symbols

Topic	Symbol	Description
AIS target (sleeping)		An isosceles, acute-angled triangle should be used. The triangle should be oriented by heading, or COG if heading missing. The reported position should be located at centre and half the height of the triangle. The symbol of the sleeping target should be smaller than that of the activated target.
Sleeping (activated) AIS target with neither reported heading nor COG		Sleeping (activated) AIS target with neither reported heading nor COG should be presented as acute isosceles triangle oriented toward the top of the operational display area with one line crossed through the symbol.
Activated AIS target including dangerous target		An isosceles, acute-angled triangle should be used. The triangle should be oriented by heading, or COG if heading missing. The reported position should be located at centre and half the height of the triangle. The COG/SOG vector should be displayed as a dashed line with short dashes with spaces approximately twice the line width. Optionally, time increments may be marked along the vector. The heading should be displayed as a solid line thinner than speed vector line style, length twice of the length of the triangle symbol. Origin of the heading line is the apex of the triangle. The turn should be indicated by a flag of fixed length added to the heading line. A path predictor may be provided as curved vector. For a "Dangerous AIS Target", bold, red (on colour display) solid triangle with course and speed vector, flashing until acknowledged.
AIS target – true scale outline		A true scale outline may be added to the triangle symbol. It should be: Located relative to reported position and according to reported position offsets, beam and length. Oriented along target's heading. Used on low ranges/large scales.
Selected target		A square indicated by its corners should be drawn around the activated target symbol.
Lost target		Triangle with bold solid cross. The triangle should be oriented per last known value. The cross should have a fixed orientation. The symbol should flash until acknowledged. The target should be displayed without vector, heading and rate of turn indication.
Target past positions		Dots, equally spaced by time.
AIS Search and Rescue Transmitter (AIS-SART)		A circle containing a cross drawn with solid lines.
Selected AIS ATON		Selected target symbols should be presented as broken squares indicated by their corners, centred on the selected target symbol.
Selected AIS-SART		Selected target symbols should be presented as broken squares indicated by their corners, centred on the selected target symbol.
Lost AIS ATON		Lost target symbols should be presented as crossed lines centred on the target symbol. The lines should be drawn using a solid line style and should flash with the required colour red until acknowledged by the user.
Lost AIS-SART		Lost target symbols should be presented as crossed lines centred on the target symbol. The lines should be drawn using a solid line style and should flash with the required colour red until acknowledged by the user.
AIS SAR aircraft		An AIS SAR aircraft should be drawn with a thin solid outline with the same basic colour as used for target symbols. The symbol should be oriented in the direction of the COG.
AIS SAR vessel		If provided, a search and rescue vessel should be presented by having a circle with cross drawn with a solid line inside the standard activated AIS vessel symbol.

Table 4: Associated target symbols

Topic	Symbol	Description
Associated target		The user may select to present associated targets (i.e. activated AIS targets associated with tracked radar targets) as either activated AIS target symbols (see symbol: "Activated AIS Target Including Dangerous Target") or tracked radar target symbols (see symbol: "Tracked Target including Dangerous Target").
Associated target alternative AIS target symbol		Alternatively, activated AIS target symbols representing associated targets may be modified by circumscribing a circle around the symbols' isosceles triangle.
Associated target alternative radar target symbol		Tracked radar target symbols representing associated targets may be presented with larger diameter circles modified by inscribing an isosceles triangle inside the symbols' circle.

Table 5: Other Symbols

Topic	Symbol	Description
Plotted position		A plotted position (Fix, EP and DR) should be presented as a circle with crossed lines centred at the position. The length of the crossed lines should be the diameter of the circle. The circle and crossed lines should be drawn using a thin solid line style. The position should be labelled with time and an indication of its source for example GNSS, L (Loran), R (Radar range), V (Visual bearing), VR (Visual bearing and Radar range). If the position is an estimated position, it should also be labelled with the letters "EP". If the position is a dead reckoned position, it should also be labelled with the letters "DR". Alphanumeric text used to label the position should be the same basic colour as the symbol.
Line of position	Examples show the default symbol for a water tower	A line of position (LOP) should be presented as a single line originating from a charted object and extending towards own ship. The bearing of the LOP should be referenced to the CCRP. The LOP should be drawn using a thin solid line style. The LOP should be labelled with time. If the LOP is transferred, it may also be labelled with the letters "TPL" for transferred position line. Alphanumeric text used to label LOP should be the same basic colour as the line. A LOP range observation will be an arc.
Monitored route		Dashed bold line, waypoints (WPT) as circles.
Planned or alternate route		Dotted line, WPT as circles.
Trial manoeuvre		Large T on screen.
Simulation mode		Large S on screen.
Cursor		Crosshair (two alternatives, one with open centre).
Range Rings		Solid circles.
Variable Range Markers (VRM)		Circle. Additional VRM should be distinguishable from the primary VRM.
Electronic Bearing Lines (EBL)		Dashed line. Additional EBL should be distinguishable from the primary EBL.
Acquisition/ Activation area		Solid line boundary for an area.
Event mark		Rectangle with diagonal line, clarified by added text (e.g. "MOB" for man overboard cases).
Tidal stream	Examples show default symbol for a point	A tidal stream should be presented as a single line with three arrowheads. The line should originate from the charted position for which a tidal stream table (or tidal stream data) is available. The line for an actual tidal stream should be drawn using a thin solid line style. The line for a predicted tidal stream should be drawn using a thin long dashed line style. The arrowheads for a tidal stream should be drawn using a thin solid line style. The tidal stream should be labelled adjacent to the line with the effective strength and time, ideally on opposite sides. Alphanumeric text used to label the tidal stream should be the same basic colour as the line.
Mariner entered danger	Examples show the default symbol for a mariner entered danger highlighting a dangerous wreck at an unknown depth bounded by a rectangular danger highlight and an outcropping of land bounded by a user-entered danger highlight	A danger highlighted by a mariner should be presented as a polygon bounding a geographic area designated as dangerous to navigation, or as a poly-line creating a boundary around such an area. The boundary of the polygon, or poly-line, should be drawn using a thick solid line style. Recommended colour: red. The polygon, or bounded area, should be filled with a transparent fill using the same colour as the polygon or poly-line.
Look-ahead alarm highlight	Example shows a depth area shallower than safety contour and a dangerous wreck within the look-ahead safety check area	The graphical indication in the chart area of an alarm condition (A11.4.4 and 11.4.6, MSC.232 (82)) should be presented as a polygon or poly-line on the boundary of the area or point object causing the condition. The polygon or poly-line should be drawn using a thick solid line style with recommended colour red. The bounded area should have a transparent fill of the same colour.
Look-ahead indication highlight	Example show point (wreck), restricted area and line (fish stakes)	The graphical indication in the chart area of warning or caution conditions (see A11.4.4 and 11.4.6, MSC.232 (82)) should be presented as a polygon or poly-line on the boundary of the area or point object causing the condition. The polygon or poly-line should be drawn using a thick solid line style with recommended colour yellow and adjacent thin lines of black on either side for visibility against a white (Day) background. The bounded area should not be filled.
Danger bearing	The drawing is not to scale. The example shows the default symbols for a light and a dangerous wreck at an unknown depth.	A danger bearing or clearing line should be presented as a single line with an arrowhead directed at the base of a charted object. The line should be drawn using a thin solid line style with the required colour red. A danger bearing should be labelled with its bearing. The letters "NMT" should be used to indicate "not more than". The letters "NLT" to indicate "not less than". Alphanumeric text used to label the danger bearing should be the same basic colour as the line.
Meteorological information		Meteorological information symbols consist of two parts: the weather station symbol; and reference point and the wind shaft. The weather station symbol should be presented as a circle with "W" inscribed inside it. The circle should be centred at the position derived from the site location report binary message. The circle should not be more than 6 mm in diameter, drawn using a thin solid line style and using the same basic colour as AIS AtoN. The reference point symbol should be presented as a dot. The dot should be more drawn using a thin solid line style and using the same basic colour as AIS AtoN. Alphanumeric text may be used to label the weather station. The optional wind shaft should be used to represent wind force and direction as defined by WMO No.485, Appendix II-4, the surface plotting model. If wind force and direction is not available then there should be no environmental symbol. The wind shaft should be not more than 3 times the diameter of the weather station symbol. The length of barbs and pennants should not exceed the diameter of the weather station symbol. The wind shaft should be drawn using a thick solid line style and using the same basic colour as AIS AtoN. The wind shaft is directed along the axis of the wind towards the centre of the station circle and stops at its circumference. Wind is represented by barbs and solid pennants. The full barbs representing 5 m s−1 or 10 kn, the half barbs representing 2.5 m s−1 or 5 kn and the solid pennant representing 25 m s−1 or 50 kn. All pennants and barbs lie to the left (clockwise) of the wind shaft in the northern hemisphere and to the right (counter clockwise) of the wind shaft in the southern hemisphere. Barbs are at an angle of 110° to 130° from the wind shaft. Pennants are triangles with their bases on the wind shaft. A calm should be indicated by a circle drawn around the weather station circle. Missing wind speed should be indicated by placing an "x" at the end of the wind shaft in lieu of the wind barbs. Note that the source of meteorological information may be AIS ASM function identifier 26 or 31 (SN.1/Circ.289), etc.
Tidal and water level information		Tidal and water level information symbol consist of three parts: tidal symbol; tidal flow symbol; tidal gauge symbol. The tidal symbol should be presented as a diamond with "T" inscribed inside it. The diamond should be centred at the position derived from the site location report binary message. The diamond should be drawn using a thin solid line style and using the same basic colour as AIS AtoN. The optional tidal flow part of the symbol should be used to represent tidal speed and direction. If tidal speed and direction is not available then there should be no tidal flow symbol. The tidal flow symbol should be drawn to the direction of the tidal current and using the same basic colour as AIS AtoN. The optional tidal gauge part of the symbol should be used to represent availability of water level information. If water level is not available then there should be no tidal gauge symbol. The tidal gauge symbol should be drawn using a thick solid line style, transparent fill and using the same basic colour as AIS AtoN. Note that the source of tidal information may be AIS ASM function identifier 31 (SN.1/Circ.289), etc.
Signal station		Signal station should be presented as a diamond centred at the reported position of the signal station. The sides of the diamond should be the same basic colour as the AIS AtoN symbol. The symbol should be labelled with text "SS" centred in the diamond and the colour of the label should be the same colour as the symbol. Note that a signal station is a station capable of transmitting marine traffic signals. The source of signal station may be AIS ASM function identifier 19 (SN.1/Circ.289), etc.
Route information broadcast		Route information is as a series of waypoints connected by one or more legs. Leg lines on the route information should be drawn using a thin dotted line style. They should have a centred solid triangle with equal length of each side and should be the same basic colour as the AIS AtoN symbol. Solid triangle is centred on visible part of each leg. Leg lines on the route information may be labelled adjacent to their line with their course. The label should not interfere with text used to label the waypoint. Alphanumeric text used to label a leg line should be the same colour as the leg line. The colour of route type "mandatory route" should be different from other route types. Note that the source of route information may be AIS ASM function identifier 27 or 28 (SN.1/Circ.289), etc.
Berthing data		Berthing assignment should be presented as a box with the "BERTH" inscribed inside it. The box should be centred at the position derived from the berthing data message. The box should be drawn using a thick solid line style and should be the same basic colour as the AIS AtoN symbol. Note that the source of berthing data may be AIS ASM function identifier 20 (SN.1/Circ.289), etc.
Clearance time to enter port		Clearance time to enter port should be presented as a box with the "CTE" inscribed inside it. The box should be centred at the position derived from clearance time to enter port data message. The box should be drawn using a thick solid line style and should be the same basic colour as the AIS AtoN symbol. Note that the source of clearance to enter port may be AIS ASM function identifier 18 (SN.1/Circ.289), etc.
Area notice		Area notice point symbol should be presented as a box with "AN" inscribed inside it. The box should be centred at the position derived from Area notice message. The box should be drawn using a thick solid line style and should be the same basic colour as the AIS AtoN symbol. Area notice area symbol should be presented as a series of lines bounding a geographic area. Connecting lines should be drawn using the thin dashed line style and using the same basic colour as the symbol itself. The area should be filled with a sparse pattern of Area notice point symbols. Drawing priority of Area notice symbol is below Maritime Safety Information (MSI). Note that the source of the area notice may be AIS ASM function identifier 22 or 23 (SN.1/Circ.289), etc.
Air gap		Air gap symbols consist of two parts: the air gap symbol the air gap gauge symbol The air gap symbol should be presented as a diamond with "A" inscribed inside it. The diamond should be centred at the position derived from the site location report binary message. The diamond should be drawn using a thin solid line style and using the same basic colour as AIS AtoN. The air gap gauge part of the symbol should be used to represent availability of air gap information. If air gap is not available then there should be no air gap gauge symbol. The air gap gauge symbol should be drawn using a thick solid line style, transparent fill and using the same basic colour as AIS AtoN. Note that the source of the air gap/air draught information may be AIS ASM function identifier 26 (SN.1/Circ.289), etc.
Environmental report		The environmental report symbol should be presented as a diamond with "ENV" inscribed inside it. The diamond should be centred at the position derived from the site location report binary message. The diamond should be drawn using a thin solid line style and using the same basic colour as AIS AtoN. Note that the source of environmental information may be AIS ASM function identifier 26 or 31 (SN.1/Circ.289), etc.

Table 5.1: Improved symbols for portrayal of AIS Aids to Navigation (AIS AtoN)

Type of AIS AtoN (Type of code in AIS msg. 21)	Symbol (Physical)	Symbol (Virtual)	Description
Portrayal when indication of type is not selected			Solid diamond (Shown with chart symbol. Chart symbol not required for radar.) Note: Applicable only for Physical AIS AtoN
Default, type not specified (0) Reference point (1) Light, without sectors (5) Light, with sectors (6) Leading Light Front (7) Leading Light Rear (8)			Physical: Solid diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position
Fixed structure offshore/obstruction (3) Light Vessel/LANBY/Rigs (31)			Solid diamond (Shown with chart symbol. Chart symbol not required for radar.) Note: Fixed structure offshore/obstruction and Light Vessel/LANBY/Rigs versions are not applicable for Virtual AIS AtoN
Racon (2)			Solid diamond with double circle of black inner circle on the top of diamond Note: Racon version is not applicable for Virtual AIS AtoN
Emergency Wreck Mark (4)			Physical: Solid diamond with cross on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and cross on the top of diamond
Beacon, Cardinal N (9) Floating, Cardinal Mark N (20)			Physical: Solid diamond with 2 triangles, one above the other, point upward, on top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and 2 triangles, one above the other, points upward, on the top of diamond
Beacon, Cardinal E (10) Floating, Cardinal Mark E (21)			Physical: Solid diamond with 2 triangles, one above the other, base to base, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and 2 triangles, one above the other, base to base, on the top of diamond
Beacon, Cardinal S (11) Floating, Cardinal Mark S (22)			Physical: Solid diamond with 2 triangles, one above the other, point downward, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and 2 triangles, one above the other, points downward, on the top of diamond
Beacon, Cardinal W (12) Floating, Cardinal Mark W (23)			Physical: Solid diamond with 2 triangles, one above the other, point to point, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and 2 triangles, one above the other, point to point, on the top of diamond
Beacon, Port hand (13) Beacon, Preferred Channel Port hand (15) Port hand Mark (24) Preferred Channel Port hand (26)			Physical: Solid diamond with rectangle, short side up, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and rectangle, short side up, on the top of diamond
Beacon, Starboard hand (14) Beacon, Preferred Channel Starboard hand (16) Starboard hand Mark (25) Preferred Channel Starboard hand (27)			Physical: Solid diamond with triangle, points upward, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and triangle, points upward, on the top of diamond
Beacon, Isolated danger (17) Isolated danger (28) Beacon, Safe			Physical: Solid diamond with 2 circles, one above the other, on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and 2 circles, one above the other, on the top of diamond
Beacon, Safe water (18) Safe Water (29)			Physical: Solid diamond with circle on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and circle on the top of diamond
Beacon, Special mark (19) Special Mark (30)			Physical: Solid diamond with bold outlined "X" on the top of diamond (Shown with chart symbol. Chart symbol not required for radar.) Virtual: Dotted diamond with cross hair centred at reported position and bold outlined "X" on the top of diamond

Table 5.2: Portrayal of AIS AtoN indicating off position or failure

Type of failure condition	Symbol (Physical)	Description
AIS AtoN indicating to be in Off Position		Failure is indicated using yellow caution colour for the basic diamond part of the symbol with cross hair centred at reported position and for text "Off Posn" in top of the Physical AIS AtoN. Note: Physical AIS AtoN indicates realtime EPFS position of drifting AtoN (obstacle).
AIS AtoN indicating Lights failure		Failure is indicated using yellow caution colour with text "Unlit" in top of the Physical AIS AtoN.
AIS AtoN indicating Racon failure		Failure is indicated using yellow caution colour with text "Racon err" in top of the Physical AIS AtoN

Table 5.3: Portrayal of AIS AtoN indicating the absence of a charted Physical AtoN

Type of failure condition

Symbol (Virtual)

Description

AIS AtoN indicating the absence of a charted Physical AtoN

The absence of a charted AtoN is indicated using yellow caution colour for both the basic diamond part of the symbol and for text "Missing". The basic diamond part is always empty without symbol of the type of the AtoN.

Note: This case is communicated as a combined state of "Virtual" and "off position". Type of absent AtoN can be determined be the underlying charted object, or selecting the Virtual AIS AtoN Object.