# INT-1 Symbol Reference — Sections P (Lights) and Q (Buoys / Beacons) ## INT-1 Section Q — Buoy Shapes | Code | Shape | Notes | |------|-------|-------| | Q20 | Conical buoy (nun buoy) | Pointed top; IALA Region B = green starboard | | Q21 | Can buoy (cylindrical) | Flat top; IALA Region B = red port | | Q22 | Spherical buoy | Ball-shaped | | Q23 | Pillar buoy | Any superstructure on small platform (lantern, topmark, radar) | | Q24 | Spar buoy (spindle) | Long thin pole, nearly vertical | | Q25 | Barrel buoy (tun) | Cask / drum shape | | Q26 | Major floating light | LANBY / light vessel; large platform with full light structure | --- ## INT-1 Section Q — IALA Lateral Marks ### IALA Region A (Europe, Africa, Asia, Australasia) | Mark | Colour | Shape | Topmark | Light | |--------------|----------|-------------|------------|--------------| | Port (left) | Red | Can/Cylinder| Red can | Red: any rhythm | | Starboard (right) | Green | Conical | Green cone point up | Green: any rhythm | | Preferred channel to stbd (modified port) | Red + green band | Can | Red can | Fl(2+1)R | | Preferred channel to port (modified stbd) | Green + red band | Conical | Green cone up | Fl(2+1)G | ### IALA Region B (Americas, Philippines, Japan, South Korea) | Mark | Colour | Shape | Topmark | Light | |--------------|----------|-------------|------------|--------------| | Port (left) | Green | Can/Cylinder| Green can | Green: any rhythm | | Starboard (right) | Red | Conical | Red cone point up | Red: any rhythm | | Preferred channel to stbd (modified port) | Green + red band | Can | Green can | Fl(2+1)G | | Preferred channel to port (modified stbd) | Red + green band | Conical | Red cone up | Fl(2+1)R | > S-57 attribute CATLAM: 1=port, 2=starboard, 3=preferred channel to stbd, 4=preferred channel to port --- ## INT-1 Section Q — Cardinal Marks (IALA, same both regions) | Mark | Colour (top/bottom) | Topmark | Light | Meaning | |------------|-----------------------|----------------------|------------------------|---------| | North (N) | Black over Yellow | 2 cones point UP | VQ or Q (continuous) | Pass to the north | | East (E) | Black / Yellow / Black| 2 cones base-to-base | VQ(3) 5s or Q(3) 10s | Pass to the east | | South (S) | Yellow over Black | 2 cones point DOWN | VQ(6)+LFl 10s or Q(6)+LFl 15s | Pass to the south | | West (W) | Yellow / Black / Yellow| 2 cones point-to-point | VQ(9) 10s or Q(9) 15s | Pass to the west | > S-57 attribute CATCAM: 1=N, 2=E, 3=S, 4=W --- ## INT-1 Section Q — Other Special Marks ### Isolated Danger Mark (S-57 layer: BOYISD / BCNISD) - Colour: Black with one or more red horizontal bands - Topmark: 2 black spheres (one above the other) - Light: Fl(2) White - Meaning: Isolated danger with navigable water all around ### Safe Water Mark (S-57 layer: BOYSAW) - Colour: Red and white vertical stripes - Shape: Spherical, pillar, or spar - Topmark: Single red sphere - Light: Iso W, Oc W, LFl W 10s, or Morse "A" (. ―) W - Meaning: Safe water on all sides (mid-channel, landfall) ### Special Purpose Mark (S-57 layer: BOYSPP) - Colour: Yellow - Shape: Any (X topmark optional) - Light: Yellow, any rhythm not used for other marks - Meaning: Special feature (traffic separation, spoil ground, cable, military, etc.) ### Emergency Wreck Marking Buoy (IALA / AISM) - Colour: Blue and yellow vertical stripes (alternating) - Shape: Pillar or spar - Topmark: Single upright yellow cross - Light: Al.Bu.Y 3s (alternating blue and yellow) or VQ(4) Y + VQ(4) Bu - AIS: AtoN transponder transmitting - Meaning: Newly discovered dangerous wreck --- ## INT-1 Section P — Light Characters | Abbreviation | Full name | Description | |--------------|--------------------|-------------| | F | Fixed | Continuous steady light | | Oc | Occulting | Light longer than darkness; Oc(2) = group of 2 eclipses | | Iso | Isophase | Equal light and dark periods | | Fl | Flashing | Single flash, dark > light; Fl(3) = group of 3 | | LFl | Long Flash | Flash ≥ 2 seconds | | Q | Quick | 50–60 flashes/min; Q(6) = group of 6 | | VQ | Very Quick | 100–120 flashes/min | | UQ | Ultra Quick | ≥ 160 flashes/min | | Mo | Morse code | Dots and dashes; Mo(A), Mo(U), etc. | | FFl | Fixed + Flashing | Steady light with superimposed flashes | | Al | Alternating | Changes colour; Al.WR = alternates White/Red | ### Light Colours | Code | Colour | |------|---------| | W | White | | R | Red | | G | Green | | Bu | Blue | | Vi | Violet | | Y | Yellow | | Or | Orange | | Am | Amber | ### S-57 LITCHR Numeric Codes (used in ENC data) | Code | Abbreviation | |------|-------------| | 1 | F | | 2 | Fl | | 3 | LFl | | 4 | Q | | 5 | VQ | | 6 | UQ | | 7 | Iso | | 8 | Oc | | 9 | IQ (interrupted quick) | | 10 | IVQ (interrupted very quick) | | 11 | IUQ (interrupted ultra quick) | | 12 | Mo | | 13 | FFl | | 14 | Fl+LFl | | 15 | Oc+Fl | | 25 | Al.Oc | | 26 | Al.LFl | | 27 | Al.Fl | | 28 | Al.Grp | ### S-57 COLOUR Numeric Codes | Code | Colour | |------|----------| | 1 | White (W) | | 2 | Black (K) | | 3 | Red (R) | | 4 | Green (G) | | 5 | Blue (Bu) | | 6 | Yellow (Y) | | 7 | Grey (Gy) | | 8 | Brown (Br) | | 9 | Amber (Amb) | | 10 | Violet (Vi) | | 11 | Orange (Or) | | 12 | Magenta (Mg) | --- ## INT-1 Section P — Leading Lines / Range Lights | Code | Description | |---------|-------------| | P20.1 | Leading lights / range lights: two lights (front and rear) forming a transit. Solid line on chart = the recommended track. | | P20.2 | Any two objects in line constitute a transit bearing. | Leading line light: has the S-57 attribute ORIENT (bearing in True degrees). The backend emits a LDLINE GeoJSON LineString feature projected along that bearing for rendering.