Actually I'm very surprised (read skeptical) of the precision and firmness of the claims in this article.

For example "...the nautical mile – 1.852 kilometers – was introduced in the 15th century..."

For one thing, there was effectively no international standardization on other units in the 15th century. Indeed different countries did not even agree on the current calendar date. So the claim that the knot was precisely international defined in the 15th seems incredible.

Also, the diameter of the earth was quite controversial in the 15th century (Columbus notoriously used a very low-ball figure to raise funds for his westward expedition to China). So it seems unlikely a precise figure for the length of a minute of arch could be agreed on and less likely that it would be accurate.