ride the crest of the wave

Some days we gracefully ride the crest of the wave all the way into shore, and the next day it crashes over us and takes us under. Which waves we catch and which ones catch us is anyone's guess.

I believe that had I continued to ride the crest of the wave of success from my initial springboard of The Facts of Life fame, I would not have become the deeply compassionate human being that I am.

Similarly, a person on a surfboard desiring to ride the crest of the wave in a path parallel to the beach would have to move at this same phase velocity.