From britaññica it said time and money. They didn’t have either to switch over from the industrial period and never did. Also from my own person reasoning i think most of the world uses not US customary, so to make stuff more accessible. hope this helps!
I dont know the answer i just want brainy points<span />
A reference point would be something not on the ship which could be used to calculate distance traveled.
Answer: C.) A lighthouse on a nearby Island