Animus fragments are collectibles found on nearly every island and location in the game. There are 200 Fragments scattered around. While sailing the seas, you may be given the option to look at a nearby island by pressing up on the D-pad, indicating that there is a collectible located on it. You can then stop the Jackdaw and swim to the island to collect the fragment.

You must collect them all to complete Abstergo Challenges and as a reward 'Deceased Crew Cheat' will be unlocked for you.

Most fragments are easily collected by running or jumping to them. Some are more difficult to get to, but you can always use the environment to reach them. Look for forked trees, lines, or cliffs nearby.

Here are some tips to help with specific challenges:

• Some Animus Fragments can only be gotten by taking a Leap of Faith. This is the same leap you take off any survey point. Look for a haystack or pile of palm leaves to give you a pointer where to jump.
• One of the trickier fragments is in Kingston, on top of the chimney of the guarded mansion. Climb up on the chimney and jump straight up. You simply hold the R1 (PS3) or R2 (PS4) button and then press X to do a straight hop. On PC, hold shift and press the space bar.
• Another tricky fragment is found in the Smuggler's Den off the coast of Kingston. You'll see it behind locked wooden doors near the walkway. You cannot blast open the door, don't waste your time. To get to it, go back in the water and find the underwater tunnel that leads directly to the area.