Having trouble uploading in the mod section, so download this file.
http://www.mediafire.com/file/0u8hq8..._sea_chart.rar
Rename your south_china_sea_chart.png as a backup first!
Unpack and put the new file here....c:\Program Files (x86)\Steam\steamapps\common\Cold Waters\ColdWaters_Data\StreamingAssets\default\cam paign\maps\"add file here"