River sailing
Some rivers have sailing, like the Hudson, especially where it widens out to several miles in the area called the Tappan Zee. But an awful lot of rivers have strong currents, varying water levels due to both natural flows and management of dams, and are relatively narrow. If there is a steady 3 or 4 knot current downriver, and you have to tack back upriver, you probably will make little or no progress at all in a sailboat. For example, using some very rough math, if you are making 6 knots through the water, traveling at a 45 degree angle up river, your VMG to the destination would be just over 4 knots before taking the current into account. But if the opposing current is 3 1/2 knots, your true VMG is 1/2 knot. So when you sail 4 miles downriver, it takes less than 30 minutes (at 9 1/2 knots: 6 knots through the water plus 3 1/2 knot folowing current); the return trip would be 8 hours! And in most rivers there is little destination variety. It works well on the Hudson because of its great breadth and because it is tidal quite far from the sea, so there is not the unrelenting downriver current found in many rivers.