Setting
Being a city in the water most land walkers are given amulets before taking a ship with the capabilities of diving. The amulets give land walkers small magical traits which allow theirl lungs to take in water like air. The amulets only work when near the Pillar of Water, which is where Tarnia is located.
One should note that Tarnia is not a complete water city. Many of the buildings and certain areas do not have any water at all. Water is repelled from certain area by the Pillar of Water.