Jackie. Thank you for the link. In the ocean some corals and fish have fluorescent qualities which show up at night. When shining a Uv dive light on them they will light up with color and brightness, while everything else remains darker, much like the yen note in the advertisement. It would be interesting to see what effect a red light has on coral. Never seen it myself but it might be fun. The Wurkkos with three different lights is a great idea, provided the beams are bright enough for diving. In terms of underwater Uv, it would be interesting to see the difference between 395 and 365nm.
Waiting for HS20 review and teardown and don’t understand which side is for throw which is for flood? It define messed up. It can be nice host for modding but not in this price range .