The following is an aerial shot of Hat Rai Lay Beach:
The rock formation on the right side of the first picture on this thread is the same rock formation that can be seen like a big finger in the center/left of this picture. The beach these people were enjoying was to the left of the finger, and to the right of the other rock formation.
The mountains in the first picture above can be clearly seen in the upper right corner of this picture. You can also clearly see the angle that the wave was coming in without being blocked by the hills.
Thanks dead. That was the type of photo I was looking for to display the terrain, but I kept finding only close ups of the formations and some beach pics(where you could still see that cliff). Looking at it from the air, I am left wondering if what we see in the bottom right of the tsunami pics(rock looking thing on the ground is the edge of that formation that is underwater in the left of the beach you mentioned--if so, wow, that water was way way out before it hit).