[OpenSeaMap-develop] Sounder offset in depth contours beta

[Christian W. <weg...@me...>]

Hi Jens. 

The depth contours (beta) in map.openseamap.org look great already! Good work.

Alas because they are not respecting the transducer offset yet, the shown depths differs from the actual depth. In my area this is 1.2m for example, as my transducer is set to depth below keel. See: http://map.openseamap.org/?zoom=18&lat=52.49607&lon=13.47775&layers=BFTFFFFFFFF0FFFFFFFFTT

To build more trust in the depth shown at OpenSeaMap from the beginning, it could be great to show the more realistic depth already in the beta. Which we could if we take into calculation the the depth offset given with the upload.

Besides where two ships with different depth offsets delivered tracks, the depth contours are disrupted by interfering artifacts.
See dottet line with different offset in http://map.openseamap.org/?zoom=18&lat=52.48805&lon=13.48614&layers=BFTFFFFFFFF0FFFFFFFFTT

I know you are busy to integrate the tidal deviations, which is very complicated. 
However wouldn’t it be easy to add/substract the transducer offset which is fix for each track?

Thanks again for your great work!

Regards, Christian