Could Speed be added?

Problem/Motivation

I'd like to be able to track the speed that an item can travel. This would be for land, sea, air, space, and hovering.
Hovering might be a little weird, but the other 3 would be awesome.

Land: m/s (meters per second), ft/s, mph & km/h or kph
Sea: knots, m/s
Air: knots, Mach, m/s
Space: m/s, km/s, c, AU/day, AU/year, factor (factor of the speed of light)