The wall of water in this video below gives you an Idea of the terror faced by many. It looks like it is a wall of water that is 8-10 meters in height (24-30' )
http://homepage.mac.com/jlgolson/thai.wmv
Once again I am unsure how long this link will be up, Over 10TB have been downloaded in the past 24 hrs.
The video attached you can see the water recced back into the sea before it engulfs the 100' of beach. (note it is on wmv format)