The present work consists of modelling and stress analysis of a three-bladed underwater vehicle propeller. Since operational costs for underwater testing are very high, a high ending software is preferred for modelling and for obtaining first-hand information on propeller performance. Static structural analysis is carried out computationally after considering suitable boundary conditions. The main objective is to carry out a comparative study of stresses on propellers made from two different composite materials–carbon/glass fibre reinforced plastics (CFRP/GFRP). In recent times, composite materials are more efficient as propeller blade material than conventional metallic materials due to their lightweight, high strength, and long durability. From the analysis, it is observed that stresses, as well as deflection on GFRP are comparable to those on CFRP propeller with lesser cost involvement. Modal analysis is also performed to find natural frequency and mode shape in each case.