The Underwater Ship*
Freya disappeared from the onlookers' sight.
Eren's ship, sailing through the River Lithe, sank deeper into the water until it reached the river's bed.
Despite the ship's descent, a giant air bubble surrounded it, keeping water out. This bubble allowed an unobstructed view of the underwater world.
Eren's water-element attainments allowed him to control the nature of the water around him. His thoughts molded it according to his needs. He did not need any spells to create the air bubble but relied on his attunement to water to prevent it from entering the ship.
This was an exciting opportunity to explore the underwater region, a world less explored by the citizens of Edin. However, the only two passengers onboard Freya didn't seem to be very interested in the unique tour they were having.