Ship of Sorrows Explorer Achievement takes place in North West part of Straits of Devastation, SW of Strait of Malediction. The event is underwater, in the submerged ship that is laying on its side.
There are veteran mobs, as well as couple of regular mobs patrolling the area, thus be careful with pulling and killing the mobs. Their respawn time is short, so try to be as fast as possible. You can try a quick run for the achievement, skipping all the mobs, but looting the grand chest will be hard since a veteran mob is guarding it. You’ll need approximately 10 minutes to finish this achievement.