The effect of water absorption and corrosive sea water on the failure response of an angle ply glass fibre reinforced-epoxy composite oriented as [0/0/90/45]s has been experimentally investigated. The specimens were first tested in unimmersed conditions, and afterwards another group of specimens was immersed in sea water for 200 days. The experiments were performed using some parameters for the pinned and bolted specimens. The specimens were tested under pre-load moments of 3 Nm and 6 Nm. The results point out that the pre-load moments increase the failure load. Moreover, immersion of the composite specimens into the sea water under preload moments can cause a notable decrease of the failure load.