Killer Whale With Background (Incomplete)

Ok, i couldnt resist! I was meant to wait until i'd finished my last model to start on the backgrounds, but i found a great tutorial on how to make the sea so i just had to give it a go.

Its not quite complete yet. Im finding it difficult to get a background image of the sky that doesnt stretch when i apply it. I also need to change it so that the merge between the sea and sky is more seemless. And finally, because of the way the lighting has been angled, the textured effect i have on the whale is not showing on the side facing the camera. Im sure this can easily be fixed, but i have no idea how. I'll have to get some help later! Oh yeah, and i need to add some splashing effects by the tail to make it look more realistic.

For anyone who is interested, here is the tutorial i used:

http://www.youtube.com/watch?v=tE44k7d_FtI