Thank you for your reply. Ok then, seems like I need to get to know to configure the ESC via VESCTool.
Instead of custom build battery with cells etc. I was thinking about to use 2 of theseTuning 20.000 mah - 12c. I have seen that on a build here. What is your opinion about?
I will definitely go with a waterproof motor. The one from flip sky seems to to be perfect for my skills/budget.