(of the way in which waves or wave-like object move) lazily / (of the way in which waves or wave-like object move) in an undulating fashion / (of the way in which waves or wave-like object move) gently / (of the way in which waves or wave-like object move) slowly

(of waves) swell slowly / (of waves) roll calmly

recall

recall

good lesson for the future

good lesson for the future

later introduction

later introduction

be about to get on / be just about to board

be going to get on / be about to get on / be in the act of riding