I seem to have developed a nautical theme here which was totally unintentional. Here are some pictures of my latest acquisition, the clockwork Sea Wolf submarine made by Sutcliffe. I had one of these as a kid and recently got this one for purely nostalgic reasons. It is a metal toy with minimal detail but it looks neat.
The clockwork motor still works and the sub dives by virtue of its forward motion and downwards pointing hydroplanes. When it slows down, its buoyancy brings it back up again. The key fits into a winder hidden beneath the rubber bung on the conning tower. Neat huh?
Here is a short video https://www.youtube.com/watch?v=wBJlL81lA6o