Intimate river cruises are becoming increasingly popular and luxurious. Next month, the 12-stateroom Aqua (866/603-3687; aquaexpeditions.com; four-day cruises from $1,950 per person, double) will be the first ship to navigate the Peruvian Amazon—and in style, no less. Inside, Lima-based designer Jordi Puig incorporates contemporary touches such as a glass-enclosed dining room and slate-gray walls in the cabins. And chef Pedro Schiaffino, of Malabar restaurant in Peru’s capital, whips up grilled dorado and steamed yucca. During the cruise, naturalists lead trips through the surrounding flooded forest on smaller rafts.