Surf fin fixing system

A surf craft including a body with a fixing element embedded therein, said fixing element being of material of greater strength than that of the surf craft body and having a fixing cavity therein, a fin attached to the surf craft, said fin having a pair of lateral surfaces and an end surface, the end surface of the fin abutting against the lower surface of the body in the region of said fixing element, the fin having a fixing formation extending from its end surface, said formation being engaged within the cavity of said fixing element by releasable means laterally engaging said formation, said surf craft body being covered by a skin of fibre-reinforced plastics, a cavity provided in said body between the inner end of said fixing element and the skin of the craft on the side of the craft opposite the fin, said cavity being filled with a hardenable material.