I really enjoyed the naval battles of ACIII, but in some ways I felt like Ubisoft didn't take full advantage of these sections. I was discussing the concepts with my friends the other day and I thought how awesome it would be to build up a naval fleet, rather than having simply the Aquila.
Imagine that during a battle, you could ram larger ships, and, providing you've dealt enough damage, Connor could leap from his ship to the enemy ship. You would then have to engage in a mini-boss fight with the enemy captain, and if you kill him, the enemy sailors will surrender (you could only do this to the final ship left; boarding while a fleet is firing on the Aquila from all sides would not work well), and you would have a brand new ship to add to your Assassin fleet!
The DLC would add a statistics system to your fleet. You'd need to manage how many sailors man each ship, and certain recruitable sailors will boost your allies' strength more (I think of Metal Gear Solid: Peace Walker, where you could recruit enemies and add them to Mother Base). You could then send your ships and their crews to other countries in a system akin to the Brotherhood or Revelations recruit missions.
Once you have ships in your fleet, you can choose to transfer upgrades from them to others or to the Aquila, or purchase brand-new upgrades. Ships from certain countries might also have access to unique weapons or advantages.
Not only that, but you could have your friendly ships accompany you into battles. I imagine a huge naval battle with the Aquila leading an Assassin fleet straight toward a huge Templar fleet, then chaos ensues. THAT would be AWESOME.
Since we're very early in the DLC stage of ACIII, I hope that something like this will be implemented eventually.
"Courage is resistance to fear, mastery of fear- not the absence of it." - Mark Twain PSN ID: F33R_K1LL5