SOUNDINGS IN METRES
Reduced to Grevelingen datum (=NAP-2dm)
The datum can vary between
NAP-1dm and NAP-3dm

HEIGHTS IN METRES
Above Grevelingen datum

SUPPLEMENTARY MARKS
In these waters supplementary marks for pleasure craft 
and special marks for areas meant for waterskiing, kite surfing, 
jet-skiing and fast motorboats and areas under the Nature Conservation 
Act are on station from ± April-October.

The beacons mark at least the 
1,5 metre depth contour (±April-October).

SPEED RESTRICTIONS
In these waters restrictions for sailing with fast
motorboats and waterskiing are in force.

WINTER-BUOYAGE 
From ± December-March buoyage may be replaced by winter-buoyage. 
In severe winters buoyage is withdrawn. Buoyage will be replaced 
in order of importance. In spring it is possible that not all 
channels are already buoyed as charted.