Build a swimming pool?

In the late 1980s the Endless Pool® was developed by James Murdock, in an attempt to build a less-expensive alternative to the SwimEx. This machine places the water-moving equipment - a large propeller encased in a stainless steel box and powered by a remote hydraulic pump, and its stainless steel water circulation tunnels - inside the body of a vinyl-lined metal pool. Its stream of water is narrower than that of the SwimEx, though the swimming experience is comparable. A couple of copy-cat systems have sprung up since its introduction.