Architects Design Amazing Floating Sauna. Big Branzino is a floating sauna designed by Thomas Sandell and Johan Strandlund at Swedish firm sandellsandberg architects. It can travel at a speed of five knots and is bespoke built to enjoy saunas and entertain guests in the beautiful nature of the Stockholm archipelago. The design revolves around its distinct shape, where the bow shape is the central theme throughout. The lowest point of the arch creates warmth and closeness to the glow of the fire, and as the arch rises to the sides it allows the stars of the night sky to be admired from the inside. Big Branzino was hand built by Master carpenter Leif Persson at Kungsör Shipyard, Sweden. The exterior is a rugged pine to blend in with surrounding nature and the interiors and furniture is made of western red cedar, due to its great characteristics for sauna and outdoor use. The heart of the vessel is the sauna oven and was custom designed in close collaboration with the blacksmith, with glass surrounds. Its roof terrace is subtly lit by a concealed led light along the wall top, allowing uninterrupted views of the night sky and the great views of the surrounding archipelago.