It is used in the quest for the new cleric spell Temperance.
This drops off lots of mobs in Dulak's Harbor. I've seen it drop from any of the 5 boat crews and any of the various types (fisherman, engineers, and scrubbers) you'll find on the docks as well. Typically, clearing any boat will result in one emblem dropping but don't count on it.
If you can't get a boat to camp, OOC the zone that you are looking for one and you will generally get a reply (if people are nice) within 30 minutes tops. If you go this route be sure to bring someone that will invis you or some invis potions unless you want to fight through lots of mobs in which case you probably won't get there before it rots.