GEBCO layer disturbs the chart

[Nautic]

Since years, the GEBCO layer makes all other layers "milky". This is due to the fact that the GEBCO tiles are rendered in a way where the land areas are white, and they are put on top of the base layer with a certain level of opacity.

Now Martin submitted a patch:

//GebcoDepth
layer_gebco_deeps_gwc = new OpenLayers.Layer.WMS("deeps_gwc", 
"http://osm.franken.de:8080/geoserver/gwc/service/wms",
{layers: "gebco_new", format:"image/png"},
{layerId: 6, isBaseLayer: false, visibility: false, opacity: 0.4});

Please can somebody integrate this code?

[ehrenfeu]

There have been a lot of things going on regarding the GEBCO layer, see e.g. the corresponding thread on the developer's mailing list:

• depth colouring is now working and will be deployed on the main webserver (hopefully) soon (see Update online map to integrate recent developments. #55)
• marine contour shading has been adjusted to generate PNG's with transparent land areas based on the GEBCO 2014 data (see the announcement)

Still open / new bugs:

• shallow water zones are rendered in rather dark grey, which adds an ugly dark
  region on all coasts, see e.g. Mallorca / Menorca or the German Bight (see attached image 1)
• due to the relatively low resolution of the contour shading data, and the dark grey rendering, a pretty annoying "sawtooth" effect is visible on many coastlines for zoom levels 3 through 11 (see attached image 2)

Image 1 (Mallorca)

Image 2 (Menorca)