Depth map from NVE
General information
These maps are built up based on scanned depth maps and vectorized depth quotes / depth points for a selection of river stretches and lakes in NVE's lake database.
The data have different quality and accuracy and must not be used for navigation purposes.
The maps are suitable for use on lakes where there is insufficient coverage in the maps from C-Map Genesis or dybdekart.no.
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Background
This is not a service that will compete with dybdekart.no. These maps are static, they will not be updated with submitted logs. If you are actively logging in to a lake and want to make a map of this, we recommend that you use C-Map Genesis. The quality of the maps will vary greatly. Lakes / watercourses that are regulated by NVE typically have a higher quality than those that are not. Particular outlines can be very inaccurate on some maps. We can, if there is a request for it, update the outline of lakes so that it becomes more accurate, but this is a time-consuming process and we therefore do not do it until we get the request for this.
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Information about the maps and how they are produced
We download the maps in shape format. The depth range varies from lake to lake on these maps, but we want the same depth range and appearance on all the maps we make. Therefore, we use existing depth decoys to generate a 3D model of the lake bottom. On this 3D model, we place lots of points in a grid of 10mx10m, 50mx50m or 100mx100m, depending on the size of the lake. These points, together with the original depth contours turned into points, are then used as input in Reefmaster where our version of the map is made. Reefmaster has a limit of a maximum of 250m interpolation and without making extra points, the maps would therefore have lots of "holes" where there is more than 250m between the depth levels. By adding the extra points from the interpolated 3D model, we avoid this and can generate comprehensive maps of all the lakes as they appear on NVE's pages. Note that this also causes a certain degree of inaccuracy.
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Downloadable maps for Lowrance, Simrad and B&G
The maps are named as "TK <lake name> NVE "and is selected in the list of available maps on your chartplotter. The elevation interval is 5m but there is also a 1-meter scooter down to 15m. blue to light blue and covers the range 0-30m, below 30m the background is white.
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Download depth map from NVE here:
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