Upgrade your pirate ship in Assassin's Creed 4, upgraded it with more cannons, stronger hulls, and new abilities and new weapons. You can find theses upgrades at the different locations on the map in hidden chest.
via N4G: pc news feed http://n4g.com/news/1385486/assassins-creed-4-black-flag-jackdaw-elite-upgrade-locations-guide
via N4G: pc news feed http://n4g.com/news/1385486/assassins-creed-4-black-flag-jackdaw-elite-upgrade-locations-guide