According to a recent article in Maritime Journal, the US Seafighter vessel was an 80m craft designed for 52 knots with 500 tons of deadweight. Designer John Bonafoux said, “It was the first vessel designed to the new US Naval Rules. It had to take two helipads so we developed specialised aluminium extrusion for the helideck structure to minimise weight. This was double skinned, and can survive the high helo dynamic load, although the plate is only 3mm thick, a tremendous project.”
Once again, aluminium extrusions are used in design for less weight and more efficency.