Actually, the latitudes of the race are such that it cannot go out of the ring 45
o S and 60
o S. Apparently, the definition of the Southern Sea is south of parallel 60
o S. This gives a (-45
o) - (-60
o) = + 15
o = 15 x 60 = 900'. Knowing that one nautical mile corresponds to one arc minute along the meridian, this gives a corridor of width 900 nautical miles (this is
clearly stated in the rules of the race). The minimum length of the path is if they travelled along the southmost ring with radius (see figure below):
r = R cos(-60o) = R/2
This gives a circumference of:
s = 2 π r = π R
But, instead of using the radius of the Earth (a hypothetical quantity), let us relate it to the length of a meridian between the North Pole and the Equator
L (This corresponds to an arc suspending an angle of 90
o = 90 x 60' = 5,400' or, by the definition of nautical miles 5,400 n. mi.). That would correspond to quarter of a circle with radius
R on RE and would have a length:
L = R π/2 => R = 2 L/π
Substituting this in the above formula, we get:
s = 2 L
We now ask ourselves: What is the radius of a circle on a FE with this circumference. Obviously:
r = s/(2 π) = L/π = 5,400 n mi/3.14 = 1,720 n mi
This corresponds to a latitude that is 1,720' / 60 = 28.7
o south of the North Pole, or latitude of 61.3
o N.
I give you a point according to Google Maps that has this latitude:
Also, I give you these pictures: