Fish have been around for more than 450 million year’s and are remarkable creature’s, over thousand’s of year’s they have made many superb adaptation’s to survive in the marine environment. Living in the world of water is not easy, but it doe’s present some environmental opportunities as well as serious challenges. Sound for example, travel’s almost 5 time’s faster and much better in water than it doe’s in air, fish capitalize on this by having an excellent sense of hearing, using both their inner ear’s and lateral line’s to detect prey and avoid enemies. Water, however present’s a serious challenge for fish and fishermen when it come’s to vision and color, many characteristic’s of light quickly change as it move’s though the water, the first thing to realize is that the color of your lure – fly in the water is almost always different from what it is in the air, after much research the following result’s were concluded. The attenuation of light : The light that humans see is just a small part of the total electromagnetic radiation that is received from the sun, what we see is called the visible spectrum, the actual colors within the visible spectrum are determined by the wavelength’s of the light : the longer wavelength’s are red and orange : the shorter wavelength’s are green, blue, and violet, however many fish see colors we don’t including ultraviolet. When light enter’s the water it’s intensity quickly decease’s, and the color change’s, these change’s are called attenuation, attenuation is the result of two processes, scattering and absorption. The scattering of light is caused by particle’s or other small object’s suspended in the water – the more particle’s, the more scattering. The scattering of light in water is similar to the effect of smoke or fog in the atmosphere. Coastal water’s generally have more suspended material due to river input, material stirred up from the bottom, and increased plankton, because of this greater amount of suspended material, light usually penetrate’s to a lesser depth, in relatively clear offshore water light penetrate’s to a greater depth. Light absorption is caused by several thing’s, such as light being converted into heat or used in chemical reaction’s such as photosynthesis. The most important aspect for fishing is the influence of the water itself on the absorption of light , the amount of absorption is different for different wavelength’s of light, in other word’s various colors are absorbed differently, the longer wavelength’s such as red, orange, are absorbed very quickly and penetrate into the water to a much shallower depth the shorter blue, violet wavelength’s. Absorption also restrict’s how far light penetrate’s into the water, at about 3m (10′) , roughly 60% of the total light ( sun-moon ) and almost all the red light will be absorbed, at 10m (33′) about 85% of the total light and all the red, orange, and yellow light have been absorbed, this has a direct bearing on how a fish perceive’s a lure-fly, at a depth of 10′ a red lure-fly appear’s grey, and it eventually appear’s black as the depth increase’s, with increasing depth, and dimming light become’s bluish and eventually black when all the other colors are absorbed. The absorption or filtering out of color also work’s in a horizontal direction, so again a red lure-fly that is only a few feet from a fish appear’s grey, similarly other colors also change with distance, for a color to be seen it must be hit by light of the same color, and then reflected in the direction of the fish, if the water has already attenuated or filtered out a color, that color will appear grey or black, with the exception of fluorescent’s which we will come to. It should now be clear how the depth of the water or distance from a fish affect’s the visibility of your lure-fly, in extremely shallow and very clear water colors may look similar to their appearance in the air, as your lure-fly get’s just 3 feet deep or 3 feet away from a fish– or less if the water clarity is limited — the colors will start to change, often with surprising result’s. What do fish see : Scientist’s don’t know for sure exactly what fish see, their research is based on physical or chemical examination of different part’s of their eye’s or by determining how laboratory fish respond to various image’s or stimuli, physical studies of the eye’s and retinas of fish show that the majority can obtain a clearly focused image, detect motion, and have a good contrast – detection ability, a limited number of experiment’s have shown that a minimum level of light is necessary before a fish can recognize colors, another finding that need’s more study is that some fish favour a specific color, this may contradict or affirm your own fishing experiences, but remember that the attractiveness of your lure-fly is a combination of many thing’s, including motion, shape, and color. Fish usually use their sense of hearing or smell to initially perceive their prey and only use their vision in the final attack. Most fish can see in low light condition’s or dirty water, and a few can see object’s over a moderately long distance’s. The majority of fish have developed eye’s that will detect the type of colors typical of their environment, eg inshore fish have good color vision, where as offshore pelagic fish have limited color vision, and only detect a few if any colors other than black and white. This is not surprising from an evolutionary point of view, because nearshore water’s are lit with many colors, offshore water’s on the other hand are mainly blue or green and contain few other colors. The actual ability of a specific color to attract or repel fish has fascinated both angler’s and scientist’s, while there are no uniform answer’s it’s well known that color come’s into play in breeding with some species. Color suggestion’s : This is perhaps the most important point to remember, most predatory fish detect their prey by seeing the contrast of the prey against the various colored background’s, you will be faced with many different situation’s when fishing day or night, here are some point’s to consider when choosing your lure-fly= Try to consider what color your lure-fly will be at the depth your fishing: Many fish feed by looking up to the surface, in doing so they have difficulty seeing color, and the contrast of the lure-fly against the surface become’s more important, when a dark silhouette is used even against a dark night sky it provide’s the maximum contrast, and is very attractive to predator’s: Black is the least transparent color, and give’s the best silhouette, black is probably the most visible color under most condition’s: If your lure-fly has two or more colors, the darker color should be over the lighter colors, almost all bait-fish have this color arrangement, and dark over light usually make’s a good contrast: When fishing deep water the motion, noise, or disturbance it make’s might be more important than color: Increase the contrast of the lure-fly if the water is dirty, decrease the contrast if it’s clear: A good horizontal profile is important when vision condition’s are low, nighttime black, red offer good profile’s: Understanding polarized light : Recent research show’s that many fish sense polarized light, human’s do not have the ability to separate polarized from regular light. Regular light= vibrate’s in all direction’s perpendicular to it’s direction of travel. Polarized light however, vibrate’s in only one plane. When light is reflected off many non metallic surface’s, including the ocean surface, it is polarized to some degree. This explain’s how polarized sunglasses work: they block out the horizontally reflected polarized component of light from the ocean surface which cause’s most of the glare but permit the vertically reflected component to pass through. It is not fully understood why some fish have the ability to sense polarized light, but there are some interesting possibilities, being able to detect polarized light might help fish in their migration’s and ability to swim closely with other’s of the same species. The ability to sense polarized light must certainly be related to the fact that when light is reflected off surface’s, eg bait-fish scale’s, it is polarized. Fish that can detect polarized light have an advantage in finding food, polarizing vision can also enhance the contrast between almost transparent prey, and the background, making the prey easier to see. Another conjecture is that having polarizing vision can let fish see object’s that are farther away — perhaps three times the distance — as fish without this ability. If this speculation is correct, it may answer the question why some fish can feed under very low-light condition’s, and there is more polarized light at dawn and dusk, which might explain why some fish such as striped bass, seem to feed more aggressively at these times of day. If the ability to sense polarized light help’s fish to find food, then it follow’s that lures-flies that reflect polarized light should be more attractive to such fish. There are many artificial material’s that simulate fish scale’s and various tinsel’s that claim to be excellent reflector’s of polarized light. Fluorescent colors increase visibility : Fluorescent colors, especially chartreuse are very popular with many saltwater fly fishermen, under the right condition’s fluorescent colors, which are not naturally found in nature, can be very visible underwater and seen from considerable distance’s. A fluorescent color is one that will be bright when exposed to light having a shorter wavelength, eg fluorescent yellow appear’s as bright yellow when exposed to ultraviolet blue or green light. Alternatively, fluorescent yellow doe’s not appear yellow when struck by red light that has a longer wavelength, because of this unique characteristic of fluorescent colors, they don’t have the dramatic color change when fished deeper. The fluorescence of fluorescent colors is mainly due to ultraviolet (UV) light, a color that is invisible to us, humans cannot see UV light, but we can see how it bring’s out the fluorescence in certain colors. Ultraviolet light is especially dominant on cloudy, overcast day’s, and when UV light hit’s something having fluorescent material, it’s color becomes especially visible and vibrant. On bright sunlit day’s , the fluorescent effect is considerably less,and of course if there is no light, there will be no fluorescence. Research show’s that fluorescent colors are visible and distinct for longer distance’s than regular colors, and that a lure-fly with fluorescent materials often attract’s fish, to be more precise, a fluorescent color having a slightly longer wavelength than the color of the water has better long distance visibility, eg in greenish water’s, the brightest colors would be fluorescent green or chartreuse. As good as fluorescent colors maybe, they will usually not work if the fish are actively feeding on a specific bait, since it is highly improbable that the fluorescent color will resemble any color in that bait. As you can see, light and color can get fairly complicated, and are only part of the jigsaw, along with tide’s, wind, day and night, fish are not smart but you have to know how to make them react to your lure’s and flies, when your local condition’s are present.