hey guys... i have created an Under Water Scene, in which have got few rigged fish from poser & a nice ecosystem

the problem which i m facing is, when i animate the scene. all animation is done except water. the sea material i have used is Tropical Water & have activated "Displaced water Surface" option. But when i keep my cam beneth water... the water doesnt seem to b moving n whn its above water level... yaa it does animate...

so guys how can i solve my prob... pls help me out....