How can I find specific factions' ships?

I seem to collect quests which involve destroying a certain faction's ships. Currently I need to destroy both Athenian and Pirate ships.

However, now that I have a quest they all seem to vanish.

Are there specific tips and tricks to finding certain ships? Such as off the coast of regions controlled by the faction?

I am working on the assumption the Athenian ships are blue sails and Pirates black.

Solution 1:

There's no clear-cut way to find a bunch of ships for one faction. The only, albeit somewhat unreliable, way, is to head to the coasts and surrounding waters of a region controlled by the faction you are looking for. Concentrations of ships seem to be a bit higher near docks, but even out in the waters I regularly encounter patrols of 2-3 ships.

Ships can be identified as follows:

• Spartan: red sails
• Athenian: blue sails
• Pirates: black/grey
• Merchants: white