Under sea particles looped animation.
You can use on interfaces, websites, animations and intros, DVD,CD menus, AE projects, etc…
Note: How to make it web site background ?
flashden video files comes with mov. file (mine are HD), so all you need to do is convert mov. file to .flv file.
I recommend you http://activeden.net/files/9089/index.html to use this as source.
Also don’t forget to resize the flv file for example 640×480 or lower to reduce size of animation for web.