Here is some basic info first.
Quote:
http://www.d20pfsrd.com/equipment---final/vehicles
A barge is a flat-bottomed, usually rectangular boat designed for hauling cargo along inland waterways. Barges are usually simple affairs, some are no more than glorified rafts, although they can be up to 200 feet long. The larger ones usually sport an enclosed space, like a little building on one end of the ship with cots, a table, and chairs inside. Smaller barges in relatively shallow water are usually poled along by rowers
Vehicle : Barge
Maximum Speed: 1/2 mile/hour or 5 miles/day (poled or towed)
Length : 80–150 ft.
Passengers : 50–150
Rafts, barges, keelboats, and rowboats are most often used on lakes and rivers. If going downstream, add the speed of the current (typically 3 miles per hour) to the speed of the vehicle. In addition to 10 hours of being rowed, the vehicle can also float an additional 14 hours, if someone can guide it, adding an additional 42 miles to the daily distance traveled. These vehicles can’t be rowed against any significant current, but they can be pulled upstream by draft animals on the shores.
Okay taking all that in. the average barge boat can go 5-8 miles a day according tot he stats (5 normally. 8 with a current)
How in the hell does something so slow, suddenly get a 42 mile a day boost from an extra 14 hours of work? Wouldn't it be closer to the 5-8 miles and a bit more for the extra time?
