You need more information before you can search for the Black Opal. Go look around the pirate ship for any information.
Step 1. Go to the pirate ship, find the map, and bring it back to LidunA Raider who is keeping watch at the Anturoon Sentry Post in Anturoon Crossing of Ishalgen. She is very cunning and always trying to find a way to make some extra cash.. (You need to collect: A Treasure Map)