A protective module for use as a water shielding part of a barrier, said barrier being adapted to be positioned between a body of water and an area of land to be protected. The protective module has a main plane and a first, second, third and fourth side, which sides define a main surface of the protective module, in the main plane of the protective module, the first and second sides being arranged opposite each other. A method of manufacturing a protective module according to the invention, concerning a barrier made up of interconnected protective modules and a barrier system including two or more protective modules, the protective modules being adapted to be joined together in such a manner as to form a barrier.