The present paper shows an evaluation of a joining method for a composite material which is widely used in the nautical industry, the glass reinforced plastic (GRP), and it brings to discussion how the joining characteristics change as a function of the scarf angle. The literature suggests values from 1:6 to 1:60 depending on the tension requirements. Tensile tests were done for laminated specimens joined with the scarves of 1:6, 1:12 and 1:20, simulating real FRP boat repairs. The results were compared to the original continuous material. From the results, the scarf of 1:12 showed the best repair, with the closest strength values from the original material; the scarf of 1:6 had the worst results. The specimens with the scarf of 1:20 showed an inconclusive result, as statistically they did not differ from the results of 1:12, thus being unable to confirm part of the theory that says that a scarf of 1:20 would be better.