From the diving bell head north through the seaweed patch and into the first shipwreck guarded by jellyfish to open your first Treasure. Exit out the other side of the ship and use the seaweed to conceal yourself from the shark as you make your way to the air barrel to grab some air.
From the air barrel, wait for the sharks to move away and then use the burst beam to propel yourself forward to the next wreck and enter, avoiding the jellyfish, and open the next Treasure. Exit the wreck from the other side when the shark moves away and swim to the ocean floor and use the seaweed to head to the air barrel to the south.
Enter the nearby ship through the doorway by the air barrel and head straight until you hit a wall with a Treasure on the other side. Pick up the Animus Fragment and then exit through the stairs, not the side of the ship, and grab the Treasure by the captain's cabin before you use the air barrel. Quickly make your way up the large mast, using the mast and rigging to break line of sight to the sharks, and grab the Animus Fragment. You will now need to angle yourself down to the other half of the ship at the bottom of the sea and make a break for the hull.
Grab the Treasure inside the hull and wait from the shark patrolling above to move to go above deck, turn right and go around the railing and enter another part of the ship for the next Treasure with the Elite Ram Design Plans. Wait for the shark to move and head for the final Treasure before you grab the Animus Fragment and swim back to the diving bell.
