We do not know the release date of Patch 1.3 yet, but the release of the DLC “Tides Of Power” is November 4, and it will be free for all players until January 5.
The patch might include an option to keep playing your civ (might, because changes are not sure yet), and will come with a range of naval options, fitting to the DLC. This includes a harbor building, a privateer unit, a range of resources (among them crab and turtle), and new terrains.
The DLC will bring in its first part the Pirate Republic and fittingly Edward Teach as leader, together with another seafaring nation, Tonga. The second part will come later, and will include the Ottomans, Iceland and the 16th century barbary pirate ruler Sayyida al Hurra.
You can read the whole announcement here, and discuss with us here.