The ground floor of the Tower is built in stone, with the first and second floors built of brick. The brick would have originally been used as ballast on the many cargo ships which plied their trade out of Galway. The ballast was offloaded onto the quay walls when the ship was loaded with a new cargo, and the bricks were re-cycled and used in the construction of local buildings such as the Fishery Tower.

The ground floor was used to store nets and other fishing equipment, and for this reason it always had a flagged floor, which slightly sloped downwards towards the rear of the Tower to allow for water to drain away from nets and other gear which were hung up to dry. This feature has been retained in the restored building. At the slipway at the rear of the Tower, the remains of poles and metal rings can be seen, which were used to secure the large nets used for draft netting on shore.

At one time Fishery personnel lived in the Tower to monitor activity in the River, and the location of blocked up fireplaces on the first and second floors confirm that this is where the fishery workers lived, slept and ate.

The Tower has a number of interesting features. The stained glass window on the ground floor is the original window that was installed when the Tower was first built. It was in surprisingly good condition given its age, and apart from repairs to sections of the stained glass which had been broken (the correct type of glass was eventually found in Germany), very little work was needed on it. It is somewhat unusual that such an ornate window should have been included in what was very much a working building, but this was not an uncommon feature in Victorian architecture. Also typical of Victorian architecture is the fact that the staircase runs across a window on the first floor. For the Victorians, the exterior symmetry of the building was far more important than how the building looked on the inside. There are also two windows on the second floor which were blocked up at some point in the past - it is unclear when.