The Norwegian nautical chart in Lokimaps is not approved for navigation. Use an updated official paper chart or ENC, appropriate navigation equipment, and current safety information when travelling on the water.
Lokimaps shows Kartverket's raster chart service for geographic reference. The authoritative visual key is Kartverket's Symbols and Abbreviations in Norwegian nautical charts, also called Norwegian INT 1. It is a bilingual Norwegian and English inventory of international symbols plus Norwegian-specific variants.
Norwegian INT 1 is extensive because a chart symbol often combines shape, colour, line style, abbreviation, number, and surrounding context. This page explains the main groups, but it is not a substitute for matching the actual mark in INT 1.
At the closest app zoom levels, Lokimaps enlarges the last available raster tile. Larger soundings and symbols are not more precise, and enlargement cannot recover hazards omitted at the source chart's scale. The tile view also omits the full title block, edition and correction statement, caution notes, paper-chart source diagram, and ENC ZOC information needed to assess an official chart.
Scale and source quality come firstScale and source quality come first
Use the largest-scale official chart suitable for the waters. Kartverket's guide to reading a nautical chart explains that smaller-scale charts are heavily simplified in coastal waters. Enlarging a raster image does not reveal hazards that were omitted at its source scale.
On an official paper chart, the source diagram describes survey quality and age; in an ENC, Zones of Confidence (ZOC) conveys data quality. Nearby areas can be based on very different survey methods. A precise-looking sounding or shoreline does not make an entire area equally accurate.
Soundings, contours, drying areas, and seabedSoundings, contours, drying areas, and seabed
Soundings are individual depths relative to the chart's stated datum. Depth contours and colour bands divide the water into depth ranges. Drying heights identify features that are above the chart datum at some states of the tide but covered at others. INT 1 also includes abbreviations and patterns for seabed materials and the quality of holding ground.
Contours are generalized and do not describe every underwater variation. Read the least depth, nearby hazards, survey quality, vessel draught, tide, waves, and a safety margin together. Never infer a safe channel merely from empty space between soundings.
Rocks, wrecks, obstructions, and offshore installationsRocks, wrecks, obstructions, and offshore installations
Different symbols identify rocks that are always visible, awash, or submerged, along with wrecks, foul ground, underwater obstructions, wellheads, platforms, fish farms, and other installations. A danger circle, sounding, abbreviation, or colour can change the meaning of the central mark.
Submarine cables and pipelines, dumping grounds, restricted areas, and anchoring or fishing prohibitions may be shown with limits rather than a prominent point symbol. Trace the complete boundary and check its annotation before entering or anchoring.
Tracks, routes, fairways, and limitsTracks, routes, fairways, and limits
INT 1 distinguishes recommended tracks, leading lines, traffic separation schemes, deep-water routes, fairways, precautionary areas, anchorage areas, and numerous regulated or restricted limits. Direction arrows and associated notes are part of the symbol.
These lines are navigation information, not a promise of present clearance or unrestricted passage. Temporary changes, dredging, construction, traffic measures, or an altered aid to navigation may be published after a raster tile was produced.
Lights, buoys, and beaconsLights, buoys, and beacons
Aid-to-navigation symbols encode several properties. The buoy or beacon shape, colours, topmark, number, light colour, rhythm, period, height, and range can all be significant. Cardinal, lateral, isolated-danger, safe-water, and special marks should be identified from the complete symbol and abbreviation.
Light sectors and leading lights require careful reading of their arcs, colours, bearings, and characteristics. Do not rely on colour alone, particularly on a dim screen or where several symbols overlap. Kartverket notes that Norwegian charts mostly use international symbols, with a smaller number of Norwegian-specific symbols shown alongside their international equivalents in INT 1.
Tides, currents, datums, and clearancesTides, currents, datums, and clearances
Depths, drying heights, bridge clearances, overhead cables, and other vertical values are tied to charted reference levels. Tide diamonds, current arrows, tidal-stream information, and tables have separate symbols and units. Check the chart title, notes, and datum before using any number.
Norwegian official charts use WGS 84 horizontally. The vertical chart datum is Lowest Astronomical Tide (LAT) from Utsira northward, including Svalbard. South of Utsira it is generally 20 cm below LAT, except in the Oslofjord north of Drøbaksundet, where it is 30 cm below LAT. Kartverket maintains these regional details in its Miscellaneous Notices to Mariners. Never transfer a depth or clearance between areas without checking the datum printed on the official chart.
Actual depth and overhead clearance change with tide, weather, atmospheric pressure, waves, and local conditions. Consult Kartverket's current tide and water-level information, then apply a safe margin appropriate to the vessel and conditions.
Ports, services, and small-craft informationPorts, services, and small-craft information
INT 1 also covers harbour structures, berths, moorings, anchorages, pilot services, rescue and communication facilities, marinas, and small-craft services. A symbol records charted information, not live opening hours, availability, capacity, or permission to use a facility.
Keep the official chart correctedKeep the official chart corrected
Kartverket revises Norwegian INT 1 when required, and publishes navigation-critical changes through Notices to Mariners (Efs). Before a voyage:
- Use an official chart or ENC at the appropriate scale.
- Identify unfamiliar marks in the current Norwegian INT 1.
- Read the chart's scale, projection, datum, edition, caution notes, and its paper-chart source diagram or ENC ZOC information.
- Check tide, water level, weather, and applicable regulations.
- Review and apply Kartverket's Notices to Mariners (Efs).
If Lokimaps and current official navigation material differ, rely on the approved and corrected navigation source.