is in an erected configuration and the support material 130 is therefore flexed referring to sub fig1 a the support material when flexed 130 b forms a generally flat formation at the end of the bow spanning between the pair of bottom panels 112 114 in this configuration the support material 130 is under traction this is an area of the hinge 116 that is under high tension stress relative to other areas of the hinge and so a flat configuration is ideal for structural purposes significant departure from the flat configuration at this region of the hinge 116 could create a sharp fold line and potentially damage the web or sheet of the hinge line material 120 it is therefore desirable for the support material 130 to form a substantially flat configuration at any region of the hinge 116 where there is traction when the panels 112 114 are in the erected configuration in the embodiment shown in fig9 to 11 this will generally be adjacent beginning and end of curved portions of the boat hull 110 referring to sub fig1 a the position of support material 130 in a substantially un flexed position is depicted with dotted lines and referenced as 130 a sub fig1 b shows detail of the central hinge adjacent the bow area of the hull the support material 130 b when flexed as a result of the panels 112 114 being moved to the erected configuration forms a ridge 122 projecting away from an.