Hello.
There is a bug after completing the main story and getting the Achievement for defending Mistral. From what I can tell, you're supposed to talk to someone nearby the quest turn in spot, and then right around there is someone who is supposed to allow you to get on a small boat that takes you to a ship, which takes you to your next area.
I've found this person, but they tell to me 'hop in the launcher' at which point the chat end and nothing happens. I've jumped in the boat, swam around the boat, tried to swim to the main ship, EVERYTHING that I can think of and nothing is happening. Basically i'm stuck here for Heaven knows why.