Is the Flameheart Pledge Permanent?

Hello everyone, I've recently been fished back into sea of thieves and I've been told that old mate Flameheart is ubering out his new flagship, but you have to pledge your service to him.

Is the pledge permanent? Like if I finish that session, close the game and come back another time, will I still be in his service or will the game reset like a usual new session on the seas?