Boat hull, material or blank for a boat hull, and a method of producing a boat hull

A relatively stiff, but flexible blank in the form of at least one sheet for use in producing a boat hull, said blank being bendable to form the body or shell and the bottom of the boat hull, said blank forming the broadest part of the hull after being bent and formed and said blank having a center-line corresponding to the center-line of the boat hull,

• the improvement wherein:
• said blank has at least one first slot extending from one outer edge of the blank towards said center-line of the blank, said at least one first slot having opposing first edges and being in the part of said at least one sheet forming the broadest part of the hull;
• said blank has at least one elongated second slot generally extending in the direction of or parallel to said center-line, the opposing edges of said at least one second slot being joined together along the lengths thereof to form respective ends of said at least one second slot;
• said first edges of said at least one first slot merge, at a distance from said outer edges of said blank, into said at least one elongated second slot;
• and
• said at least one elongated second slot is provided, at the respective ends thereof, with enlargements or holes (25) to remove stress concentrations when the sheet is bent, which enlargements or holes are filled in after forming of said hull.

A method of producing a boat hull comprising:

• providing at least one relatively stiff but flexible sheet of material having at least one first slot extending from one outer edge of the sheet towards the center-line of the resulting boat hull, said at least one first slot having opposing first edges and being in the part of said at least one sheet forming the broadest part of the hull;
• providing said sheets with at least two elongated second slots which extend substantially in the direction of or parallel to said center-line of the resulting boat hull, said second slots being formed at a distance from said outer edges of said at least one sheet, each of said second slots having opposing edges which are joined together along the lengths thereof to form respective ends of said second slots, said first and second slots being provided such that said first edges of said at least one first slot merge, at a distance from said outer edges of said at least one sheet, into at least one of said second slots;
• providing enlargements or holes at the ends of said elongated second slots to remove stress concentrations when said at least one sheet is bent;
• bending said sheet along said center-line or parallel thereto and along the extensions of said first and second slots and joining the respective opposing edges of all of said respective slots;
• and
• filling in said enlargements or holes after the joining of said opposing edges of all of said slots.