PASSAGE PLANNING IMO recommends that all vessels navigating the Channel and Dover Strait should have on board the latest edition of BA Chart 5500 or an equivalent guide and the Netherlands Chart 1970 Mariners' Routeing Guide Southern North Sea. OIL and GAS FIELDS Production platforms and associated structures, including tanker moorings, storage tankers and platforms on pipelines, generally exhibit Mo(U) lights, aircraft obstruction lights and audible fog signals. Unauthorized navigation is prohibited within 500m of all such structures, including storage tankers which can swing about their moorings. Tankers manoeuvring in the vicinity of platforms and moorings should be given a wide berth. For further information see The Netherlands Coast Pilot (HP1) or The Mariners' Handbook. 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. TRAFFIC SEPARATION SCHEMES AND ROUTEING For the latest information on individual schemes and IMO mandatory routes for certain tankers and other vessels, see the Netherlands Coast Pilot(HP1) or ADMIRALTY Sailing Directions. WETREP Tankers of more than 600 dwt carrying heavy crude oil, heavy fuel oil or bitumen and tar and their emulsions are required to participate in the Western European Tanker Reporting System (WETREP). See ADMIRALTY List of Radio Signals for further details. BOUNDARIES The international boundaries shown on the chart are approximate. PRECAUTIONARY AREAS Vessels entering the NORTH HINDER JUNCTION, RIJNVELD, SCHOUWENBANK jUNCTION, MAAS CENTRE, MAAS JUNCTION and IJMUIDEN precautionary areas should navigate with extreme caution as vessels on route to and from TSS off Texel, TSS North Hinder North, IJmuiden, the Westerschelde and Europoort may be merging or crossing. VESSEL REPORTING For details of VTS Maas Approach, Scheldemond (VTS-SM), Den Helder and IJmuiden Vessel Traffic Service, see the Netherlands Coast Pilot (HP1) or ADMIRALTY List of Radio Signals. HELICOPTER OPERATIONS Pilot transfers by means of helicopter may be expected in the MAAS CENTRE precautionary area, in the NORTH HINDER JUNCTION precautionary area and in the IJmuiden Approach area. See the Netherlands Coast Pilot (HP1) or ADMIRALTY List of Radio Signals for details. ROUTEING For information about recommended routes and the IMO-adopted Mandatory Ships' Routeing System under SOLAS regulation V/8, see the Netherlands Coast Pilot (HP1) or ADMIRALTY Sailing Directions. Also see Netherlands Chart 1970 Mariners' Routeing Guide Southern North Sea. A least depth of 26m (2000) was found in the DW routes near the south end (around 52°N). The least depth in the (western) routeing system via TSS off Botney Ground was 27m (1998) and in the (eastern) routeing system via TSS West Friesland 23m (1995). DEEP DRAUGHT VESSELS For vessels drawing 20.7m (68ft) or more, on their way from Dover Strait NE-ward, Netherlands Authorities recommend use of a Selected Route. For details see Deep Draught Planning Guide. Greenwich Buoy to Europoort (HP8).