The route they needed to take was one not used by sutori that much, since it went through various towns and such before reaching the ducks where they would proceed to board a ship to the land of Forests because they wanted to avoid the land of Earth, then even though they would rather not, the ship would still need to stop at the Land of Wind, then after a fast stop at an island not to far off from the shores of the Land of Wind, they can then proceed on a long journey to the Land of Night. From there, they can make their way to tak Numbra on their own.
Since academy days, every sutori is made to memorise the different maps of different lands and the different travel routes that exist. This was to make sure that whenever they were away from the tak on a mission or any other occasion, they wouldn't get lost and would be aware of where they were at anytime. Of course, as in any world, it is always important to know the general geography.
