SUBMARINE CABLES AND PIPELINES Mariners are advised not to anchor or 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. DEPTHS AND AIDS TO NAVIGATION The channels and depths shown on this chart are subject to frequent change. The buoyage and other aids to navigation are adjusted accordingly. For the latest information see Notices to Mariners or consult the pilotage authorities. NATURE RESERVES Entry into the nature reserves shown on this chart is defined by numerous restrictions and prohibitions. For further details see www.rwsnatura2000.nl. HARINGVLIETSLUIZEN Red lights are shown during sluicing. During sluicing the water level of the Haringvliet may fall 5 dm in one hour.