Cavitation is a phenomenon that occurs when the pressure of a fluid drops below its saturated vapour pressure. Even though cavitation could be used in some applications in a beneficial way, it poses serious adverse effects in the marine propulsion field. The explosion of formed cavitation bubbles in the wake field of the propeller puts large stresses on the propellers blade causing blade erosion in the long term, costing the marine industry millions of dollars annually for maintenance. It also causes vibrations and noise in ships, which for some cases require the propulsion system designers to minimise during the propeller design stages. Non cavitating flow and cavitating flow are studied in the research, using a common CFD tool that uses RANS approach. The effects of altering the pitch ratio on sheet cavitation is studied in cavitating flow using the INSEAN E779A propeller. The study used ANSYS Fluent for the simulation and only one blade is considered in the simulation. Periodic boundary conditions are applied for the 4-bladed propeller. The propeller is simulated in conditions set by the Wageningen worksop and the domain size is based on the cavitation tunnel size used in the measurements of the torque and thrust. The flow considered is uniform and has a speed of 5.808 m/s, propeller rotational speed 36 rps, advance coefficient 0.71, and cavitating flow at cavitation number 1.763. For the cavitating flow, the Zwart-Gerber-Belamri cavitation model along with the k-ε turbulence model are used. Pitch ratios of 0.8, 1.0 and 1.5 are considered and analysed. The results show an increase of the extent of sheet cavitation on the blade surface with an increase in pitch ratio.