'Haru. We haven’t swum in the sea for a long while now, right?'
Suddenly, Makoto says it, his gaze directed towards the sea. Haruka stopped himself before saying that it’s because Makoto doesn’t swim in it.”
High Speed! 2 Chapter 8 “Light” confirming that Nanase Haruka giving up the ocean for Tachibana Makoto is, in fact, 100% canon.
(translation by janeypeixies)