Thank you Txesmi

The following seems to work as well, is there a reason?

Code:
float4 texShove = tex2Dlod(waveSampler,float4(inTex.x,inTex.y,0,0));
float3 offset = float3(600,0,0);
inPos += mul(offset,matWorldInv );  // matWorldInv



matWorldInv is the inverse.