In Build: Grand Soleil GS80 Custom Sloop A custom built 80-foot sloop is currently under construction by Italian company Grand Soleil. It is called the GS80 and is currently being built to naval architecture design by Ceccarelli Yacht Design. The construction is in carbon to ensure a light 30-tonne displacement. The yacht is in build at the yard in Fano, Italy and started off build last Summer and is expected to be completed by this Summer. Once completed, the GS80 will make her world debut later on at the Cannes Yachting Festival.