This summer my family purchased two stand-up paddle-boards, otherwise known as SUPs. We took these boards out onto the lake at my cottage and were able to stand up in the middle of the water! Although not quite the same as surfing, you could still feel the waves underneath the board which is a huge component of physics. Every time the board went up or down it was because a pulse went through the wave. When the board went it up it was because it hit the crest, and when it went down it was because there was a trough (both equal in amplitude from the baseline). When boats would drive around where we were paddle boarding, the waves would get very big underneath because the two different waves met and their amplitudes combined to make one big amplitude (due to the law of superposition), which made it very hard to keep balance. The waves also carried energy that caused them to crash against the beach shore and make the paddle board move in certain directions. All in all, stand up paddle boarding is a fun activity for exercise or just to pass the time that involved a great deal of physics!