(80's movie) Two boys went to a small pond, and one of the boys goes into the water with the old scuba gear (the one with the big bubble helmet, and the long air hose). Well the boy who goes into the water, something happends and he never comes back up. And at end of the movie a large mechanical crane with lots of moss on it so it looked like a sea monster, and the missing boy is inside the mouth. Any ideas? Thank you!

Sounds like one of the most asked about movies on the Internet: Frog Dreaming (http://www.imdb.com/title/tt0091810/).