In response to your call for underwater toys. [Above] is a copy from the internet of a toy I had when small, a Disney 20,000 leagues under the sea tin submarine. This was made in a variety of colours; when wound it dived under the water and surfaced again. Great toy, wish I still had it.
The purple sub above is a plastic clockwork bath toy (works well, although tilts to one side when running!). When wound and released, the propeller turns and the periscope rotates.
Also two from recent years. The small grey submarine [above] was marketed as a pencil sharpener with "bronze effect". I sanded it down, trimmed off a surplus of guns, filled the underside with milliput, then painted it in the style of a 50s-60s toy. Final touch was the piece of cotton rigging. It now adorns my workroom mantlepiece.