In the Netherlands, we have two buoyage systems: the SIGNI system on inland waterways and the IALA-A system at sea. Let’s start with the buoyage system SIGNI and end with the only difference in the buoyage system IALA-A system.
In both systems we have lateral (buoyage at the edge of fairways) and cardinal buoyage (indicating a wreck, sandbank or other obstacle). Buoys float and beacons are set on the ground. There are buoys (with light), barrels (no light).
Marking and buoys always have the following characteristics:
- Day mark = Shape (pointed, blunt, convex, pillar)
- Lighting character and colour
- (Sometimes) top sign
- Colour (green, red, black, yellow, white)
- Radar reflector
- Marks: the abbreviation of the fairway Number
Buoyage light characters
The faster the light characters the more dangerous. The period is the cycle of light and dark phases. The different types of light characters are:
- Q=Quick Flash=flicker light (VQ=Very Quick and UQ= Ultra Quick)
- Fl=Flash=glare light (Lfl=Longflash)
- ISO=Isophase=Isophase light (ISO 2s = 1 second on and 1 second off)
- Oc=Occulting=Interrupted-light (group interruption = multiple interruptions in 1 period)
- Mo=Morsecode=Morsecode F=Fixed=Fixed light
Buoyage direction
The direction is towards the sea in the SIGNI system (inland water) and towards land in the IALA-A system (at sea). We start at sea with a safe water buoy indicating the start of the channel. When we enter the harbour from sea, we have the green, pointed odd-numbered buoys to starboard and a red blunt even-numbered buoy to port. So we then sail in the direction of the IALA-A system. If we then sail into the estuary, we enter the SIGNI system and suddenly sail against the direction. So the direction is a theoretical term, which you will rarely have to use in practice, as it applies both at sea and on inland waterways. So you always sail into a port “red on red and green on green”. To starboard we have a green boarding light (and green buoys) and to port we have a red boarding light (and red buoys). Another mnemonic is “A sailor leaves the sea with his heart bleeding.” His heart is on the left and he colours the left buoys red.
Ports
Ports and junctions may be marked with or without lights. When entering, the port side will see a red white horizontal striped marking, possibly with a red light, and the starboard side a green white horizontal striped marking, possibly with a light.
Additional marking
Additional marking indicates a kind of cycle path outside the main channel for pleasure boats.
Light lines and sector lights
Looking towards the harbour, we can tell if we are sailing in the middle of the channel by looking at the line of lights. These are 2 lighthouses, the front one being lower than the back one. If we see the 2 lights perpendicular to each other, we are in the middle of the channel on the light line.
When objects other than lights are used, we call it a guide line.
Sometimes the fairway is indicated by a sector light. This is a light that shines a different colour over the different sectors. For example, we can see from the chart that if we are in the channel, we see white light. If we are to the right of the channel we see a green light and if we are to the left of it we see a red light.
Cardinal marking
Cardinal marking is marking of obstacles on wide waterways. A north cardinal means safe fairway north and an obstacle south of the buoy. The top marks point to part on the buoy that is black. The lights are like the dial of a clock (3, 6 and 9). The LFL clearly distinguishes the south cardinal from the west cardinal.
Separation of navigable waters
In the SIGNI system, there are 3 separation buoys:
A round buoy, above green and below red with a pointed top sign.
A round buoy, red above and green below, with a blunt top sign.
A round buoy with horizontal red and green stripes, with a round top sign. For waterways of equal importance.
Special marking
Special marking indicates a special area such as an anchorage area, practice area, fishing area, speedboat area, competition areas, etc. The colour is yellow and the top sign a horizontal cross.
Isolated danger
Isolated danger buoys are black with red band. The top sign consists of 2 black spheres. The light is a white group flashing light. The mark is the abbreviation or name of the obstacle (e.g. name wreck, BANK).
Safe waters
Marked safe fairways are in the middle of the safe fairway. You can therefore pass them left and right at an appropriate distance (see the chart for that). They are round and red white vertically striped and have no top sign in the SIGNI to avoid confusion with the round separation buoys. As a light, they have a white ISO 8s or LFL. The mark is the abbreviation or name of the fairway.
IALA-A
At sea there is the IALA-A system and the separation of navigable waters / fairways is indicated in a different way by: Lateral separating bouys or cardinal separating buoys:
Example 1: Red lateral separation buoy
Example 2: Green lateral separation buoy
Example 3: Cardinal separation with waterways of equal importance.
