Yes Surfing is kosher. There's no reason for anyone to argue that it isn't.
And yet, the Times is genuinely surprised that a rabbi can surf, perhaps based on the artificial assumption that surfing is not a kosher sport, and a rabbi would not engage in it. It's a contrived bias and it also shows how narrow the conception of rabbis and rabbinical lifestyles has become.
The article is "A Rabbi’s ‘Spiritual Playground’ Extends to the Surf - NYTimes.com" and the author is astonished that a rabbi could be interested in or participate in surfing. [Hat tip to Yitz!]
There is no basis for the assumption. See my surfing posts on this blog.
I've been interested in surfing since I was sixteen. I use surfing as a metaphor in my book, "God's Favorite Prayers" where I speak about the "perfect wave of prayer" that I sought in my travels around the world.
My cover design for that book is based on the iconic Endless Summer poster.
Talmudic analysis: A slow news day at the end of the summer resulted in a silly straw man story about a rabbi who breaks the imagined mold and engages in a cool activity.