The Hidden Blade Assassin's Creed in Depth

I'm currently doing a low synch run in AC4, based on the original idea for a low synch run in AC3, by Slembroccoli.

Since only failing the main missions optional objective seems to easy to me, I decided to include the Abstergo Challenges. These don't add anything to the final synchronization score, but I wanted to have some sort of extra challenge. Basically, the goal is to play to the end of the storyline (I intend to continue until after the credits), failing all the optional objectives the game throws at me, and trying to complete as few Abstergo Challenges as possible. Without even starting, I already completed two of those: 'own 5 different figureheads' and 'collect a treasure map'.

Anyway, you may speculate what my total synchronization will turn out to be, and how many Abstergo Challenges I managed to avoid/how few I completed. (Looking at you McStab, you were pretty close with the AC3 one.)

So I've completed the game at 100%, but my database is only 97% full, apparently. Any idea what I might be missing?

I am pretty positive the white whale is still outstanding, seeing as how I haven't harpooned one, but I think I've gotten every other animal. I can't imagine I wouldn't have visited every single location in the game, plus I've also hacked every computer and grabbed every sticky note outside of the animus.

Did anyone else run into this problem and, if so, what did you do to fix it?

Thanks.

I only ask because I had a fun little sequence happen to me this weekend where I began by doing something we've all done, which is to push the joystick in the wrong direction while attempting a Leap of Faith off a viewpoint and jumped to my death.

http://ca.ign.com/articles/2014/02/05/assassins-creed-4-freedom-cry-rele...