A method and apparatus for high energy rate forming of metal. A die/mould (11) of the shape to which a metal sheet (13) or panels (18) is to be formed is lined with the metal sheet (13) or panels (18) and filled with a liquid medium. A number of explosive charges are then placed at strategic locations within the liquid medium and detonated causing deformation of the metal sheet (13) or panels (18) to the shape defined by the die/mould (11). The die/mould (11) is normally buried in a pit and supported therein during the deformation process. The die/mould (11) consists of longitudinal extending ribs (12) with air spaces (15) therebetween supported by upstanding webs (16) secured to base (17). The air spaces (15) enable air trapped between the metal sheet (13) or panels (18) and the die/mould (11) to escape during the deformation process. A method of forming boat hulls using this method is disclosed.