The present invention is a device for measuring an aquatic being. The device comprises a chamber and a semi-circular scale extending from the chamber. The chamber has a viewing window for allowing the user to visually inspect whether the nose of the fish is touching the base of the chamber. Scales are provided on the outer surface of the chamber to facilitate the measurement of the aquatic being placed within the chamber of the device. If the length of the aquatic being is longer than that of the chamber, another scale is provided on an inner surface of the semi-cylindrical scale, which facilitates the measurement of the aquatic being whose length extends beyond that of the chamber.