🇧🇪 Buoyage of Ostend: put the harbour's buoys back (Belgium)
© OpenStreetMap · ODbL · Simplified map, not for navigation.
This chart shows the real buoyage of Ostend (Belgium), taken from OpenStreetMap on 2026-10-03. 6 marks are missing. IALA region A: coming in from the sea, red to port and green to starboard.
What the chart shows
At Ostend, six marks out of seven are missing: three port-hand marks (O4, O6, OH 6), two north cardinals (BA-N, OH 9) and one west cardinal (BA-W). Only the starboard-hand mark O3 is already in place. Three rock symbols flag shoals on the chart.
Belgium uses IALA region A: coming from seaward, red is left to port and green to starboard, and O3 (odd) against O4 and O6 (even) follows the R1001 numbering. A cardinal points to a feature of interest rather than a channel. The topmark tells them apart: cones point-up for north, point-to-point for west; at night, continuous quick flashing for north, groups of nine quick flashes for west.
According to the Flemish government, the harbour entrance is bounded by an east breakwater about 600 m long and by the west dam, with a channel dredged in 2010 to 8.5 m below lowest low water for ships up to 200 m. A radar tower at the end of the breakwater belongs to the Scheldt radar chain.
Revision questions in the spirit of the exam
- How do you tell a west cardinal from a north cardinal, by day and by night?
- What colour and shape does a port-hand lateral mark have in region A?
- From its number, do you leave O3 on your right or on your left when entering?
Sources
- IALA, Recommendation R1001 (ed. 2.0, June 2023) (facts restated in our own words, text not reproduced)
- OpenStreetMap and OpenSeaMap, survey of 03/10/2026 (ODbL 1.0 licence)
- Vlaanderen.be, Department of Mobility and Public Works: Ostend harbour dams and radar tower (facts restated in our own words, text not reproduced)
For practice only: do not use for navigation. Refer to up-to-date official charts and documents.
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Data: © OpenStreetMap contributors, under the ODbL 1.0, including seamarks from the OpenSeaMap project. The derived database behind these charts is published under the ODbL: real-zones.json (ODbL), ODbL 1.0. Simplified map, not for navigation.