The speed of water flow is the current.
The speed of vessels traveling over water may be measured in 'knots" (meaning nautical miles per hour).
velocity
The term for increasing speed is accelerating.
The technical term for the speed of a river is velocity.
With regard to boating, the term Speed of Advance can refer to either the speed of the boat through the water as a function of prop rotation only (no current or drift effects), or the particular speed a boat must maintain in order to cover a specific distance in a specific amount time.
Not the speed of sound.
Speed does not travel. The word speed is a general term for velocity.
Speed of light in water = speed of light in vacuum/refractive index of water
"speed" or "the speed"
"speed" or "the speed"
Instantaneous speed is speed at any instant in time.
speed
Moderato