Vertical movement, and the mount that makes half of Tyria's jumping puzzles stop mattering.
The springer is bought from a mount trader in Path of Fire, once the story has taken you through Desert Highlands. It is coin, not a collection — the grind on this one is the mastery track afterwards, not the unlock.
Complete the Highjump Ranch task region in Desert Highlands to unlock the Springer Mastery Track.
The first springer mastery is the one worth the points: it fortifies your landing, which turns a fall that would have killed you into a dismount.
