Book excerpt: In recent years compelling reasons for using a combination of steel and composites in a so-called hybrid ship hull have been voiced. A high speed boat is presently being built to evaluate performance of a hybrid hull under real sea loads. In this paper the manufacturing of the steel truss for this boat hull is described. The truss consists of bulkheads, longerons, etc. made in welded thin-walled closed stainless steel sections. Due to the small thickness of the steel, mostly 2 mm, various bungs and reinforcements were added wherever higher loads were introduced. Measures were taken to reduce fatigue issues and to make the stiff steel share loads appropriately with the compliant glass and carbon fiber reinforced composite panels.