The new Galeon 500 Fly yacht is the quick-change artist of production motor yachts. At speed, the Galeon looks like any normal flybridge—sleek, aggressive, and sexy. But at anchor, the glass windows slide into the hull sides, the bulwarks fold down, and the 50-foot Fly looks more like a 125-foot superyacht. Its designer Tony Castro—whose superyacht designs have won many awards over the past two decades—has been steadily including superyacht features as he creates new Galeon models. But the 500 Fly is the most …