Wiktionary
flatwater
a. (context canoeing English) Of or pertaining to canoe-kayak sprint races in flat water.
Usage examples of "flatwater".
Thus dependable sources of fresh water fed the area, and in rainy season the Zula, at least, would have brought new silt to freshen the soil, and in all seasons the wandering flatwater rivers would have provided a means of transportation through the marshes.