Most of the passenger river boat travels at 35 knots per hour.
How fast a boat can travel varies based on the type of boat. Some boats travel at very slow speeds like 3-4 knots, and others at 80+ knots.
Most passenger jets fly at a speed of 400-500 knots.
Some fast ferries around the world do over 30 knots.
The oldest boats in the the U.S. inventory (S-class) were pretty slow, only about 14.5 knots surfaced and 9 knots submerged. As the war and submarine designs advanced, surface speeds improved from 15 knots to 21 knots, with an averaage of around 19 knots for most. Submerged speeds remained steady at around 9 knots.
A typical speedboat can go pretty fast, with top speeds around 40 knots (46 mph). Only the really expensive boats can go faster, as they are essentially modified racing boats that can reach 80 knots or better.
5 knots
It depends on the airplane. i.e. a cessna needs around 70 knots while a Boeing 747 needs around 250 knots.
They max out at 14.7 knots
110 knots, 260 knots or 500 knots. depends on which company. if shipping, 260 knots. if passenger, 500 knots. 110 knots for "cruise" plane.
4 knots
Some planes travels around 50 knots and over. It depends on the engine type and turbine strength. Some airplanes have stronger engines so they can travel far. In this case probably some planes travel around 500 knots and over when they cruise 30000 feet of altitude and over. This mostly applies to Boeing planes. Some smaller planes like cessna only fly around 120 knots to 200 knots about.
Depending on the type of ship/boat it can be a perfectly safe speed. most modern container ships travel around at 20 - 23 knots.