Attached Link: http://members.aol.com/plants3d/aqua1.html

I would render this to ".tif", then open it in a Photoshop like application. The ".tif" has an alpha channel around the figures which can be used to cut and paste them onto an underwater background photo. If you want to create the ocean inside poser try the free models at this site: http://members.aol.com/plants3d/aqua1.html