List of locations of all skill herbs in Risen 2: Dark Waters

I am currently playing Risen 2: Dark Waters on my PC and I have played up to a certain level. Till now I have found some skill herbs which have given some boost to the skills of my pirate. I am trying to search as many skill herbs I can get but I haven’t found many till now. Also finding them takes a lot of time and thus it takes me off-rail from my main quests. Can somebody tell me how to brew these skill herbs and where can I find some more skill herbs in this game? It would be really helpful as it would save a lot of time that I spend while searching for the skill herbs.