Attached Link: http://www.3dart4u.com

To get started may like to download menno's underwater package. This contains a water material (very good as a volume or surface material) and a sky for use with an underwater scene. Adjust the fog and haze as they are fairly heavy in the default to suit your picture.

Available from:
http://www.3dart4u.com
Go to downloads and click on the whale picture

Hope this may be useful.....Dennis