Flash movie or gif/animation?

A client of mine is using GoDaddy's website template package to host/build her website. She's wanting me to, if possible, add an image or a gif, of a flash movie or some kind of animation (i'm purely guessing / taking a stab in the dark, because I have no idea of how to do this as i'm never done anything along these lines with regards creating / building websites) that involves rolling waves (ocean / water) that when they roll back reveal some text underneath. How would I go about doing that? What would I need to consider in attempting to provide such a things within the confines of a templated website set up such as this? In advance I ask that you pardon my ignorance about this as I am clueless. It does allow me to insert HTML onto the pages, not sure if this helps or not. Also, I believe they are using something called "Website Builder 7", but that's probably GoDaddy's proprietary website building tool that they offer to their customers.