Envisioned as a floating spa at sea, the 240-foot superyacht Grace E—built by the Italian shipyard Perini Navi under its Picchiotti brand—is a stunning vessel with an eco-friendly exterior and stunning interior design. The famed naval architect Philippe Briand, through his firm Vitruvius Yachts, designed Grace E, which Robb Report named 2015’s Best of the Best. It is a shining example of Briand’s effort to bring the sleek lines of sailing yachts to his Vitruvius motor yacht designs. Grace E is offered for charter by Burgess and will be cruising the Caribbean this winter. Charter prices range from $595,000 to $640,000 per week, depending on the season. (<a href="http://www.perinina…