The only public ferry service in Bolivia operates between San Pedro and San Pablo, across the narrow Estrecho de Tiquina (Straits of Tiquina) on Lake Titicaca. You can travel by launch or rowboat to any of Lake Titicaca’s Bolivian islands. Boats and tours are available from Huatajata to the Huyñaymarka islands in the lake’s southernmost extension.
There’s no scheduled passenger service on the Amazon, so travelers almost invariably wind up on some sort of cargo vessel. The most popular route is from Guanay to Rurrenabaque. Thanks to the Guayaramerín road, there’s little cargo transportation further down the Río Beni to Riberalta these days.