My surfing experience would not have me getting a boat sideways in the surf zone. Every time they were not going straight into it the boat got turned and rolled excessively. And every time they punched straight thru they had better control and no rolling. Maybe thats why they called it training.
I did get to drive a 47 and they are awesome boats. But the beatings from getting rolled in the surf zone does do damage. A chief rolled his boat in the Humboldt harbor entrance while he was doing surf training and it took out the transmission, did prop damage and basically limped back in for repairs. This happened a few weeks after the chief and I were talking about running in the surf. He hit the swell dead on and it still rolled and turned him 180 degrees. He was punching what looked like to me a 20 footer. The video of it looked like he was on a big surf board getting tossed around. The boat responded just as our surf boards do in the surf and believe me when its big we can get trashed being caught inside.
I am sure glad they train for it as it makes them better prepared for their mission. In my eyes I look at them with the same respect I have for the rescue swimmer.