This master's thesis determines the differences in the mechanical properties of composite materials made by different manufacturing methods. Thesis describes the theory of composite materials, different manufacturing methods of composites, the experiment of testing the mass fraction of fibers in the laminate and the experiment of testing specimens for tensile strength. The specimens that were tested were made of three layers of carbon fibers connected by epoxy resin. The manufacturing methods used to make the samples were: hand lay-up process, bag molding process and vacuum infusion process. The experiment of testing the mass fraction of fibers in the laminate was made according to the ASTM D 2584 standard (Standard Test Method for Loss on Ignition of Hardened Reinforced Resins). The experiment of testing specimens for tensile strength were performed according to the ASTM D 3039/D 3039M standard (Standard Test Method for Tensile Properties of Composite Materials with a Polymer Matrix). In the results of the experiments, graphs of stress and deformation for each sample were presented, from which the difference between the mechanical properties of the specimens made by the mentioned manufacturing methods was observed. The standards ISO 12215-5:2008 and ISO 12215-5:2019 were used for calculations of the modulus of elasticity E. In the discussion, the results of the calculations were compared with the actual results obtained from the conducted experiments. This covers this thesis as a whole, which should be a stimulus and path to the world of naval architecture and composite materials for current and newer generations.