How about a combination of drinks on the water and a meal on shore?
Take in the sunset over Lake Thun and the Eiger, Mönch and Jungfrau mountains while you glide over the waves in either a modern motor cruiser (2-9 persons) or a charming antique wooden boat (2-27 persons). Enjoy an aperitif with champagne and snacks on the lake followed by a fine dinner in the castle.