It seems to me to be similar to having neon lights out the front of a diner..

Are large fish not attracted to lights at night where you are?

: There have been a lot of questions on this forum about LED lights.
: My friend owns a paddleboard rental and he just installed a set
: of these LED's by Cape Ann SUP:

: http://www.capeannsup.com/nightsups.html

: I still think it's not proper, but I have to say I was pretty
: impressed with the results. They are BRIGHT! He plans to start
: doing night paddle tours of a local bay that has good night
: snorkeling. I still say proper lighting is what you need if you
: just want to be seen on the water. (red/green bow, white stern
: light) However, if you night fish or night snorkel, or if you
: wanted to turn on the lights to see what's below you at night,
: these guys sell a kit with the lights that get glassed in and a
: battery pack which gets put in a watertight compartment. It's
: made for SUP's but it would work on a kayak. I just thought I
: would share the resource. Looks like you have to call and
: inquire about the kit.

: The big mega-yachts have underwater lights on the back and we like
: to call them "ego lights." I have a personal absolute
: dislike for them, especially when the boat is at dock and people
: have them on just so their boat stands out more (hence the name
: "ego lights"), or when you're at a quiet anchorage
: enjoying nature at night and some guy has to keep the ego lights
: on all night long. Now you can paddle past the yachties, pop on
: your ego lights, and say, "Nahhhh, that's nothin', I got
: ego lights too!"

: So it's not my thing, but I have to admit I was impressed with the
: end result. For my friend it means now he can do night snorkel
: tours and turn more profit for his SUP rental. If you want
: bright underwater lights this is the ticket.

: Oh, and by the way, they do make a kit that changes colors, and if
: you put those on your kayak I am going to be forced to kick you
: in the balls. The white ones I can at least accept as having
: some sort of possibly useful function, but if you turn your
: kayak into a disco it's a mandatory ballkick and revocation of
: your cool card.

: Pic is from their site. Makes portaging at night much easier!