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light wavelength - through water?

Posted: Tue Apr 18, 2006 8:10 pm
by High4Volts
Is it fair to say the shorter the wavelength of light the farther through water light will travel or am I thinking wrong here or was that a brain fart? Does the wavelength differ with the color? Reason I’m curious is I am redoing my boat and considering adding some LED's around the outside facing down into the water. Question is what will travel farther? Do I go by color or wavelength? Has anyone seen this done before? LED suggestions?

Posted: Tue Apr 18, 2006 8:36 pm
by HighFrequency
Yes wavelength depends on colour... or rather, colour depends on wavelength. I'm not sure what colours work best underwater, but if you think about it, all the phosphorescence found in marine nature is green or blue. Darwin would say that green or blue (which have shorter wavelengths than red or orange) are better.

Why do you want leds facing down into the water anyways?

Posted: Tue Apr 18, 2006 8:46 pm
by Chris Smith
Color and wave length are the same thing.

UV attenuates in water, as do all colors or frequencies.

From memory, UV penetrates the least actively to only a few feet, [? 20 feet?] where as the white light spectrum which is mostly made up from the familiar three colors goes down as far as two hundred feet in salt water, with the red and Infra red dropping off first.

[Look up underwater photography lighting supplements for this subject on the best colors, at depth]

[Look up UV frequency and the energy needed to break down water into hydrogen ] {cold fusion and hydrogen production in sea water}

Posted: Tue Apr 18, 2006 8:47 pm
by High4Volts
For night swimming and anytime i'm out at night in the boat floating around. The LED's would not be under water. more like on the sides of the boat pointed a little out and mostly down. I wanna see that Musky before he sneeks up on me and bites my toes... lol Seriously, why not? Would like some inside the boat too for general lighting. hehe I already have my boat ripped apart. might as well add everything i can think of now while i can run wires under the carpet... :grin:

Posted: Tue Apr 18, 2006 8:53 pm
by High4Volts
So it is feasible? How does the mcd rating play in LED’s? is it the amount of lumens given off?

Posted: Tue Apr 18, 2006 8:54 pm
by Chris Smith
BLUE, as in the sky and ocean is your color. Its that way for a reason already.

Posted: Tue Apr 18, 2006 10:30 pm
by High4Volts
if i am running LED's with the boat off @ lets say 12.0v then i crank it and idle about for a bit. Now the voltage is about 13.7v. Should i just figure the resistor at the highest voltage? Or will there not be that much of a difference to tell?

Posted: Tue Apr 18, 2006 11:08 pm

Posted: Wed Apr 19, 2006 8:26 am
by Clyde Crashkop
Lights shining in the water at night will attract bait fish, which will attract that Musky. One time I was using a flash light to check trim tabs. So many minnows swarmed around that I could not see the trim tabs. This is a good thing if you are fishing.

Posted: Wed Apr 19, 2006 9:20 am
by Robert Reed
While vacationing on Tennessee's TVA lakes. I noticed a lot of night fishermen whose boats were ringed with a light string around the hull and close to the waterline. These were of a dark violet color. Were these for checking the lure upon retrieval or for attracting fish?

Posted: Wed Apr 19, 2006 10:53 am
by Newz2000
You should probably check this video out if you're thinking about using lights to keep the fish from biting your toes:

Posted: Wed Apr 19, 2006 5:13 pm
by Chris Smith
Here is a chart to help you decide the best light color for attracting the fish based on the depth penetration performance alone.

Unfortunately I don’t know if your fish are color-blind, or even color deficient to certain Colors but regardless, any light will seem black and white to them if they are,..... which will attract the fish in the dark regardless of frequency.

At 90 feet UV light from the sun is down to1% in the clearest ocean water. 200 ~ 400 nm

At 160 feet RED light from the sun is down to 1% in the clearest ocean water. 780 - 622 nm /384 - 482 thz

At 500 feet White light from the sun is down to 1% in the clearest ocean water. 390- 780 nm / 384- 769 thz

At 650 feet Blue light from the sun is down to 1% in the clearest ocean water. 492 - 455 nm / 610 - 659 nm

“Water absorbs warm colors like reds and oranges (known as long wavelength light) and scatters the cooler colors (known as short wavelength light). Image courtesy of Kyle Carothers, NOAA-OEâ€

Posted: Wed Apr 19, 2006 9:00 pm
by High4Volts
This is all really good info. Thanks to every one of you. I'll shop around for a bit to see where I can get the best deal. I think I’ll use red inside with a couple of white ones on a separate switch and I thought about ganging 2 whites a blue and possibly a green about every foot down the sides.
Anyone have any idea (this is for me to get an idea of how bright 10K MCD is) what the little LED lights they sell at Wally-World would compare to? Say a 3 bulb LED light?
That's a cool clip of the fish jumping in the boat. I think I have seen something similar to that on TLC or Animal Planet. Really funny watching the guy dodge the fish! We watched it at work over and over.

Posted: Wed Apr 19, 2006 9:41 pm