SOUNDINGS IN METRES Reduced to NAP Summer datum (April-Oct) lies between NAP and NAP-1dm Winter datum (Nov-March) lies 3 dm below NAP and may vary between NAP-2dm and NAP-4dm Kanaal door Walcheren is reduced to canal datum (= NAP+9dm) HEIGHTS IN METRES Above NAP Vertical clearances above HAT 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 1,7 metre depth contour (±April-October). Outside the buoyage of the fairway called 'VM' all kinds of fishing gear may be encountered. KATSE HEULE SLUICE Red lights are shown during sluicing. SWIMMING AREA Sailboards prohibited SPEED RESTRICTIONS In these waters restrictions for sailing with fast motorboats and waterskiing are in force. CABLES AND PIPELINES It is prohibited to anchor and trawl in the vicinity of submarine cables and pipelines. Pipelines are not always buried and their presence may significantly reduce the charted depth. They may also span seabed undulations and cause fishing gear to become irrecoverably snagged, putting a vessel in severe danger. 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 In severe winters buoyage is withdrawn.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.