Background Image Behind Footer

I’m creating a new website for a client at https://awesomewebsites4u.com

I have a nice blue background image that I would like to be in the background of the whole page. So far it is appearing behind the nav menu, header and content/sidebar boxes but I can’t get it to extend down to behind the footer.

The footer is green and I want it to remain green. I just want the blue image to continue into the footer area.

Would really appreciate your ideas.
Thanks!