[Crannogman]

Perhaps the most remarkable thing about the System International is that all its measures are derived from time, i.e the second. Originally a second was the length of a day divided by 24 by 60 by 60; now it's defined by a similar (but more precise) amount of time quantified by the radioactive decay of a Cesium isotope. The meter, originally based on an imprecise measure of the earth, is now based on a precise measure of the speed of light. The gram, originally based on the mass of a certain volume of water at a certain temperature, has evolved to the mass of a specific kilogram-defining object made of metal. Thus, Scientific Units are based on immutable reality, and can be derived in a lab independent of the original measures (indeed, in an independent galaxy). SI units also have the advantage of being made to be scaled, whereas the English/Imperial system requires use of ridiculous scales or converting units (and fail to measure tiny things). It is perhaps telling to note that English/Imperial units are now largely defined in terms of their SI counterparts. Even the supposedly concrete English/Imperial units were originally based in flawed measures of variable natural phenomena.

So SI units are vastly superior when measurements must be precisely communicated and repeatable, eg in science. Certainly Dick O'Kane did not need to know anything about the decay of Cesium to send a Japanese freighter to the bottom of the sea.