Strange result when using phoenixFDocean tex as displacement on plane

Not sure what is happening. I was following this tutorial: https://www.youtube.com/watch?v=5425bK6-d6A

I have a plane of 100mx100m and the vray displacement setup is pretty standard.

Where am I going wrong ?

by default the vray displacement have limitation 0-1, make it -100..100
or better get a nightly, this will be automatically managed when the texture sees that is used in vray displacement modifier

Thanks for that.