The Aquarium is a building located on Port Jackson in which the players can store their fish in different tanks to show other players what they've caught during their fishing career. By adding each tier to a player's aquarium, they are granted with distinct tank shapes to put their fish in. Players could also edit their aquariums by adding decorations to embellish their aquariums, but be alerted that the maximum amount of decorations placed is 800.
Players can also store baby Sea Creatures in their aquarium after obtaining an egg dropped from killing sea monsters. The baby sea monsters will only fit in the Tier 2 Aquarium tank.
Every player's aquarium starts at Tier 1. What this tier consists of are 2 side tanks which can hold 20 fish in each tank.
Tier 2 will cost the player 10,000 to unlock. What this tier grants the player is one large tank, with a capacity of 20 fish and is shared among each side of the tank, for players to put their fish in. Note that players can also place baby shark and orca eggs into this tank due to it's size in comparison to the other tanks.