Of course surfing is related to physics because of waves. Waves are a transfer of energy, so every time a surfer rides a wave they are actually involved in a transfer of energy. Also the combined effect of the interaction of multiple water waves is known as wave interference this is when two waves meet and the total displacement is the sum of the individual displacement of the waves. The waves also meet but then go opposite directions once they meet as if they never met. Also standing waves can produced in the ocean as well which is when waves of the same frequency and amplitude traveling in opposite directions meet. So a surfer is actually experiencing many physics like thinks while surfing the waves.