David wrote:

The first obvious (and reasonable) question would be, "why would you
want to do this, you couldn't see them? -- you can see koi." Well,
suppose one side of the pond was next to your living room, and had
windows into it. Like, well, the aquarium at your local zoo?

How about a cheap LCD camera, placed in a Plexiglas enclosure, that is
submersed in the pond? Run this to an RF modulator, and put it on you
TV on an unused channel, to your existing TV's.

(I'd
rather not get into all the practical issues of design and engineering
yet -- I'm only just starting to think at the very conceptual
top-level.)

It is a lot easier to keep a camera alive, and not all that hard to
remote. G Many of them will work with IR lights, so as to not disturb
the fishies as they sleep. IR LEDS could provide cheap illumination.