Port-hand mark
Red. Cylinder topmark, if fitted. Keep the mark to port when following the conventional direction of buoyage.
Light, if the mark is lit: Red light; check the chart for the light's character.
Boating glossarySweden · IALA Region A
Navigation marks – colours, topmarks and lights
Colour, shape and light help you find the right side of the mark.
Use an up-to-date chart and check Ufs (Notices to Mariners). The images are schematic and don't show every variant. Never judge depth or safe passage from a navigation mark alone.
Sweden · IALA Region A
In Sweden, the main direction of buoyage generally follows the coast from Strömstad towards Haparanda, and otherwise runs from the sea in towards harbour. The direction arrow on the chart is what counts. The images show the topmarks; the buoy itself can vary in shape.
| Navigation marks | Colour, shape and light help you find the right side of the mark. | Light, if the mark is lit: |
|---|---|---|
| Port-hand mark | Red. Cylinder topmark, if fitted. Keep the mark to port when following the conventional direction of buoyage. | Red light; check the chart for the light's character. |
| Starboard mark | Green. Cone pointing upward as topmark. Keep the mark to starboard when heading in the conventional direction of buoyage. | Green light; check the chart for the characteristic. |
| North cardinal mark | Black over yellow. Two black cones pointing up. Pass to the north of the mark. | White Q or VQ: continuous quick or very quick flashes. |
| East cardinal mark | Black–yellow–black. Cones base to base. Pass east of the mark. | White Q(3) 10s or VQ(3) 5s: three flashes in each group. |
| South cardinal mark | Yellow over black. Both cones point down. Pass to the south of the mark. | White Q(6) LFl 15s or VQ(6) LFl 10s: six flashes followed by one long flash. |
| West cardinal mark | Yellow–black–yellow. The cone points face each other. Pass to the west of the mark. | White Q(9) 15s or VQ(9) 10s: nine flashes in each group. |
| Isolated danger mark | Black with red horizontal bands and two black spheres. The mark sits on an isolated danger with navigable water all around. Keep clear of the danger itself. | White Fl(2) 5s or Fl(2) 10s: two flashes in a group. |
| Mid-channel mark | Red and white vertical stripes and a red sphere. Indicates safe water on all sides, for example at a landfall or in the middle of a fairway. | White Iso, Oc or LFl 10s. |
| Special mark | Yellow with a yellow X as top mark. Marks, for example, a cable, measuring instruments or the boundary of an area. Not primarily a navigation mark. | Yellow light with a character different from cardinal, isolated danger and safe water marks. |
Lateral marks: red and green
Starboard mark
Green. Cone pointing upward as topmark. Keep the mark to starboard when heading in the conventional direction of buoyage.
Light, if the mark is lit: Green light; check the chart for the characteristic.
Boating glossaryCardinal marks: pass on the side of the compass point in the name
Think of a clock face for the flash groups: east 3, south 6 plus one long flash, west 9. North flashes continuously without groups. The light is white.
North cardinal mark
Black over yellow. Two black cones pointing up. Pass to the north of the mark.
Light, if the mark is lit: White Q or VQ: continuous quick or very quick flashes.
Boating glossaryEast cardinal mark
Black–yellow–black. Cones base to base. Pass east of the mark.
Light, if the mark is lit: White Q(3) 10s or VQ(3) 5s: three flashes in each group.
Boating glossarySouth cardinal mark
Yellow over black. Both cones point down. Pass to the south of the mark.
Light, if the mark is lit: White Q(6) LFl 15s or VQ(6) LFl 10s: six flashes followed by one long flash.
Boating glossaryWest cardinal mark
Yellow–black–yellow. The cone points face each other. Pass to the west of the mark.
Light, if the mark is lit: White Q(9) 15s or VQ(9) 10s: nine flashes in each group.
Boating glossaryIsolated danger mark, safe water mark and special mark
Isolated danger mark
Black with red horizontal bands and two black spheres. The mark sits on an isolated danger with navigable water all around. Keep clear of the danger itself.
Light, if the mark is lit: White Fl(2) 5s or Fl(2) 10s: two flashes in a group.
Boating glossaryMid-channel mark
Red and white vertical stripes and a red sphere. Indicates safe water on all sides, for example at a landfall or in the middle of a fairway.
Light, if the mark is lit: White Iso, Oc or LFl 10s.
Boating glossarySpecial mark
Yellow with a yellow X as top mark. Marks, for example, a cable, measuring instruments or the boundary of an area. Not primarily a navigation mark.
Light, if the mark is lit: Yellow light with a character different from cardinal, isolated danger and safe water marks.
Boating glossaryHow to read a light's rhythm
- Fl
- Flashing light: short flashes with longer periods of darkness in between.
- Q / VQ
- Quick flashing / very quick flashing light.
- LFl
- Long flash. The south mark shows one long flash after its six quick flashes.
- Iso
- Day and night are of equal length.
- Oc
- A light interrupted by shorter periods of darkness.
- (3) 10s
- Three flashes in a group; the whole pattern repeats every ten seconds.
Frequently asked questions
Is red always on the port side?
Only when you are following the buoyage direction. Going the opposite way, red is on your starboard side. Check the direction on the chart.
Does a north cardinal mark show where the hazard is?
The name tells you the safe side: you pass north of a north cardinal mark. The hazard lies on the opposite side, but you need to check its extent on the chart.
Do all spar buoys have topmarks and lights?
No. Topmarks and lights may be missing. Identify the mark using the chart, colour, shape and whatever features are actually present.
Source and image policy
Sjöfartsverket: Floating navigation marks
Marinpedia's own drawings show standardised colours and topmarks. They are not copied from Sjöfartsverket's images.