If you want to see what underwater fluorescence looks like (which is what I was using the Nichia UV LEDs for),
and why some people say that it is like being in the movie "Avatar",
have a look at this video of mine:
http://www.youtube.com/watch?v=4V9TCdCbX6U
This video was made with blue light (around 450 nm) instead of UV, however,
because the fluorescence is much stronger with blue light,
apparently because marine life has adapted to the properties of water,
which is more transparent to blue light than it is to UV.
Enjoy!