I'm seeing the distance between Stanley (Port Stanley, Falklands) and Bouvet is just under 4,000 km. That is 2,500 miles.

But in a post by Adrian Ciuperca, KO8SCA on the "On All Bands" Website he says it's 1,553 miles -
LINK.
"The 2,500 Km (1,553 mile) journey to and from Bouvet, from the starting point of Port Stanley in the Falkland Islands to 54° south latitude where Bouvet Island is located, means a journey totaling 45 days of sailing in one of the most frigid and whirling waters of the South Atlantic Ocean."
That's a BIG 1,000 mile (between 4 & 6 days
each way) difference!
What am I missing here?
N0UN