The futuristic new Iris concept-yacht series from the Miami yacht-design firm Eramotive include a dazzling array of over-the-top amenities. The series comprises three different sizes: a 148-foot, three-deck version; a 246-foot, five-deck version; and a massive 418-foot, seven-deck version. Each yacht’s top surfaces and retractable awnings are lined with solar panels—broader solar-panel coverage is optional— that can collect enough energy to allow the boat to cruise at 10 knots (for the 418-foot version) withou…