For someone with such an unstable sleeping pattern, Rolf's daily routine was quite... well, routinely. With a steady daily job, and with his sons and pets in his life, he tried to do his best to keep a steady pattern. That way, he reasoned, even if something unexpected was to happen, at least it would be easy to catch up on things again.
Also, it helped him focus on his obligations rather than get too distracted with some things - like, say, what was going on between him and Luna right now. He never knew what to expect from her, but at this point this was proving to be confusing rather than exhilarating. One moment she poured her heart to him, then she kissed him, then she ran away - and Rolf, trying his best to keep a friendly distance, had no idea how to react with her attempts to shorten said distance without scaring her away again.
Right now, however, his thoughts were in the methods he ought to use to try to scan for underwater life, and how Hermione Granger, as his apprentice, could help him in that respect. He was so immersed in this that he didn't even notice who was around as he walked down the town square