|The Flounder model on display.
All the miniature construction was supervised by the head of the miniature prop department, Gaile Brown and included an 8 foot (2.4m) long mechanical whale attached to a flange wheeled dolly which traveled along an underwater track and pulled by a steel cable and a winch. It was able to dive and surface, had a working blowhole and a flapping tail mechanism along with air hoses to produce the wake and tail fluke white water effects.
A miniature version of the floating island Seastar, was built 80 feet (24.4m) wide, which employed a number of 44 gallon drums that could be partially filled with water enabling it to float at the right level. There was a matching section of African coastline 300 feet (91.4m) wide and what appears to be a close up larger scale section where two halves of a tree come together.
Added to the mechanical whale creatures was a miniature flying giant moth complete with a miniature Doctor shot against blue screen and composited against a matte painted sky and a miniature version of the giant sea snail also shot in the Sersen tank.
I remember being totally captivated by this film when I was taken to see it at the cinema as a child of around 5 or 6. I really believed that the Push me Pull you double headed Llama creature was real and I was astounded when the two bits of land and particularly the tree came together like a jigsaw.
Source: Special Effects - Wire tape and Rubber Band Style by L.B.Abbott, ASC Press 1984.