Decommissioned platform (user-supplied list), 15 NM buffer -- circle toggles with "Hide buffer circles"
OpenSeaMap: nautical marks & charts overlay
Dutch EEZ boundary (VLIZ/Marine Regions)
Belgian EEZ boundary (VLIZ/Marine Regions)
British EEZ boundary (VLIZ/Marine Regions)
German EEZ boundary (VLIZ/Marine Regions)
Danish EEZ boundary (VLIZ/Marine Regions)
Water depth: EMODnet Bathymetry, default multi-colour depth grid (off by default). Custom 30m threshold styling was attempted and reverted -- did not work.
Depth fill: same real data, filled by band (off by default)
Each cell clipped to its exact interpolated sub-shape per band (same technique as the contour lines), not a flat rectangle -- adjacent cells' edges match up, reading as one smooth region rather than a grid.
Live vessel, no type data (grey, no halo -- same as reported code 0)
Fill by vessel type once known: black=cargo/tanker/passenger/HSC/WIG, green=fishing, orange=towing/tug/SAR, yellow=dredging/diving/pilot/port tender/anti-pollution/spare, red=military/law enforcement/medical/noncombatant, white=sailing/pleasure craft. Halo is white for contrast, except black for white-fill markers.
Arrow = course over ground (fallback: true heading). Dot = no direction data available.
AISstream key is built in -- see code comments for the "no direct browser connections" caveat.
1 nm = 1,852 m
"Fully-covered" = every point of a platform's 15 NM circle boundary is covered by the union of arcs cut from it by the platforms NOT hidden by this button. Most codes in this set are exact-geometry verified hole-free; a manually-added subset is NOT verified and is known to leave real gaps when hidden -- see code comments.