Treasure chests in sequence 3 - The Port | Treasure chests AC Chronicles: China Guide

You must pass by guards to reach the ledge with a chest

CHEST 1/2 - First chest can be found at the beginning of the level, on the way to the main deck of Chinese warship. During the ship exploration you should see the chest on lower ledge which seems to be unavailable. Continue your journey to the right until you reach the place with a large hideout with bamboo curtains and two talking guards. You must reach that hideout, wait for guards to start talking again and then go left. After a while you will get to the chest, and inside you will find Scroll 3.

Reach the left ledge after leaving the ship and making a leap of faith

CHEST 2/2 - Second chest can be seen for the first time during exploration of the ship with third informant (side mission objective). The game will allow you to reach it later. After leaving the ship and landing in a haystack you will find yourself near a knob. Don't use it, instead turn left and jump to the badly visible ladder. Climb at the new ledge and take Scroll 4 from the chest.