Is this achievement bugged? Because it occured, but i took the peacfull solution. Is it now impossible in this playthrough to get another chance? I sail around with 1 morale all the time and with wounded crew members.

You have to fight the crew to get the achievement. It's also a fairly rare event since there are multiple "low morale" events.

Yeah, problem is, i don't get much events either now. Every event happens rare =(

empty your food and water then sail around.  You will hit a couple low morale issues, but eventually mutiny. 

 

Choose the attack/fight option and you get the achievement as soon as the fight starts.