Approximately 70% of our earth is covered by water, taking to the oceans and rivers to explore, is a natural part of the human spirit. Driven by curiosity and a sense of adventure, new waterway experiences are more in demand.
Taking a cruise is very popular amongst many travelers. Africa is perhaps not as well known for cruising but does have a number of select destinations with excursions.
Cruisecritic is an excellent site that covers all aspects of cruising. You can find a good selection of destinations, as well as reviews and tips that can help in making the best decision.
Adventure-Life is a very good site for river cruises. It has a clear recommended list and breaks down the choices nicely, making it easy to navigate the available options.
All that's left is venturing out into waters that have been less traveled.