The water pageant is viewable from anywhere along the beach and boat dock area at Ft. Wilderness, which is a short two minute stroll down the walkway from Hoop Dee Doo.
If you take a Disney bus to get to the HDDR, just exit the building and walk the opposite direction from the busses, or look for a lot of parked golf carts and walk towards them.
When you get to the water, stop, or you'll get wet.
There is a one-hour horse-drawn hayride that leaves after the Hoop.
If you are leaving the 7:15 Hoop show, then the hayride takes you to a secluded section of beach and sits to view the Water Pageant.
Its a nice easy ride and you don't need ressies.
Just show up near the Pioneer Hall restroom entrance (you'll see the horse and wagon) and pay a small fee ($7-8 or so) per person and take the nice ride.
(There's no actual HAY in the wagon, but there are bench SEATS so you don't sit on the wagon floor.)