© 2019 The Authors. International Journal of Nautical Archaeology © 2019 The Nautical Archaeology Society.The 15th-century IJsselcog was lifted in 2016 from the river IJssel near Kampen (the Netherlands). From stern to bow and from starboard to portside about 70% of the original wooden hull is preserved. The combined approach of analogue documentation and photogrammetry enabled the research team to reconstruct the original ship in 2D and 3D, followed by a comprehensive study of its nautical characteristics. The hull volume and height were maximized by the shipbuilders using previously unknown construction elements in cogs, such as wales and vertical riders; shipbuilding traits that are generally applied to 16th- and 17th-century carvel-built cargo ships.