Dolphins surfing

You know how dolphins like to ride the bow wave? And what do we do but make our way to the bow to watch. Well this time I stayed in the cockpit while about 30 dolphins came to play with Harmony. While there I noticed them surfing down 5 foot waves behind us and pass us as the wave did. They would travel in groups and inspect us as they passed. It all makes sense but it is the first time I had noticed and really watched it. Unfortunately, I was too busy watching to remember to take a picture so I found this video of surfing dolphins:
http://youtu.be/bWauuX_1KH8
and this one of a dolphin stampede:
http://youtu.be/AR9JX2fRk3c