Here are the trio from the catwalk. Nice shot huh? The set exterior was very tall giving the riders the feeling that they were deep under the sea. There's no way you could see the top from your omnimover car which created a very tranquil, deep sea, effect.
The Kelp plants were attached to motors that made them rise up and down with the "current" and a Gobo in front of a spotlight created the water effects. Notice the tension springs on the Kelp strands. They could be adjusted to the right setting for the effect.