Actually, they don't list them on their website. Before our trip in March, I even e-mailed them to see if I could get a pdf copy of the schedule and they told me that they would not do it because the showtimes change on a daily basis.
What I learned from these boards, though, is that a one-day admission to Sea World is actually good for two visits (provided you visit Guest Services just inside the turnstiles before you leave on your first day). So, on the day we arrived in Orlando, our first stop was to visit Sea World for a couple of hours to get the schedule and knock of a show or two so that we wouldn't be running around trying to catch back-to-back shows when we returned for a longer visit later during our trip.