Surfing the face of the tsunami would require moving nearly horizontally across the wave at a high subsonic speed. Something like 140 mph and you wouldn't be hanging ten. Maybe you could turn and go up on top.
the waves at wiaimia bay on the North Shore of Oahu in Hawaii were on average 40 ft high about six weeks ago. They staged an international surfing championship to ride those waves. There were plenty of entrees.
Please. Some of you people need some a dose of tsunami reality.
On the beach, the guy would have to surf on churning whitewater in the front part of the wave, which would be about 15 feet high and moving about 20 mph. That's obviously doable. If you look at the videos, you can see that riding in the front part of that wave wouldn't be much different from coming in on the foam after the break of a larger ordinary wave-- the ride would just last a lot longer, and carry you farther up the beach. I see no reason to doubt the guy's story.
The story says that the *next* wave was 30 feet high, but the surfer didn't ride that wave. He had met his family and moved to higher ground by that point. Still, 30 feet is almost surely an overestimation. Even if it weren't, there's no reason a person couldn't ride in front of that wave, either.
Tsunamis are very dangerous, but not for the reasons that many of you seem to think: they hit the land at enormous speeds, or they're incredibly high. They're dangerous because they're like giant, ten-foot deep flash floods that suddenly appear everywhere. That much water floats cars, knocks people over, smashes buildings, etc., but not because the wave is moving at 100 mph or something. The water's devastating because even a large volume of slow moving water can move just about anything. Look at the videos. The water's only moving 10-15 mph. Still, that's enough to wreak havoc. But a person could easily swim or paddleboard in the water. The problem is that there's no place to get out, the water's cold, you get slammed into debris or something, or you get pulled back out to sea.