Hopefully there will be more details coming out here soon on this. While I am not overly excited for Naval Warfare specifically, I am all about adding new features to a great franchise. I guess we play the waiting game now for more on this feature of Assassin's Creed III.
On a fun side note, there was also a fun marketing video also let loose on the world too. It gives no details either, but it is fun and lets you hope that one day we can actually get an Animus in the real world. Here's one science fiction I would love to see as science fact.
Naval Warfare
Animus