Problem with Parenting

I have the scene where the water is making waves using the Displace Button in Materials and changing the OffX and OffY in the IPO window. Now, I have a ship that I want to rock back and forth depending on the motion of the water. How do I so this? Is their some special Parenting involved? Please give me your comments.

Have a look here…
https://blenderartists.org/forum/viewtopic.php?t=33528&p=362884

What you’re looking for is called “Vertex Parenting”