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#1
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I'm planning on building a cajun sneak boat. I want to use it for a fishing
situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
#2
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"Gone Angling" wrote in message
... I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. How about taking a swim and looking up from under water. -- Bob La Londe Yuma, Az http://www.YumaBassMan.com Promote Your Fishing, Boating, or Guide Site for Free Simply add it to our index page. No reciprocal link required. (Requested, but not required) |
#3
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Paint it a bright color like Blaze Orange or Hot Pink. The portion you are
referring to is typically called a "hull". This isn't a joke either, rumor has it bright colored boat bottoms and side help keep bass from jumping. Which if your in a tournament is a good thing. I was told that Pro's enjoyed fishing out of the Kellogs boat because the bass didn't jump as much. Regardless of what color you paint it on somedays it will stand out on some days as weather, water clarity, and depth of the fish all have an impact on what the fish see's. An old timer who owned a lot of boats told me that he caught more fish out of a red boat than any other color. He fished the same couple of lakes for years and used that as his gauge, luckily I like red ![]() --- Chuck Coger http://www.fishin-pro.com "Gone Angling" wrote in message ... I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
#4
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This is a good topic and I'm glad you brought it up.
When you consider the light refraction coefficient of the gradients, the first thought would be a blue grey, but clearly once you run the numbers, you see quickly why that is wrong. In the CRC Handbook of Chemistry & Physics, page E-224 in my 56th Edition, I find the following formulae: (n-1) *10^7 = const1 + const2 / lambda^2 + const3 / lambda^4 where n is the required refractive index lambda is the wavelength in micron (millionths of a metre -- in the actual printed formula there are additional factors of 10^8 & 10^16 to cope with the fact that visible spectral wavelengths are usually quoted in Aangstroem) The values of the three constants in dry air at a pressure of 1 atm are const1 const2 const3 30 deg C 2589.72 12.259 0.2576 15 deg C 2726.43 12.288 0.3555 0 deg C 2875.66 13.412 0.3777 A correction is given in the source to allow for air which has a water vapour content. To a first approximation, the variation of the refractive index with temperature and pressure can be attributed to changes in gas density, and the gas density can be obtained from the ideal gas equation: (n-1) proportional to m/V = pM/RT. But that is just a first approximation, that does not hold up for more precise work. Atmospheric refraction slightly increases the observed elevation angle of a peak relative to the observer. The effect is actually quite complicated, since it depends on the precise atmospheric conditions, including atmospheric pressure, temperature, and water vapor content, and thus varies with time and the altitudes of the observer and the observed peak. Fortunately, the effect of refraction is less than ~15% of the effect due to the curvature of the Earth, and typically only increases the observed elevation angle by less than 0.1°. Refraction is caused by two effects. First, light likes to travel on the path that gets to the observer in the minimum time. (Light is, after all, the fastest thing in the Universe, so you wouldn't expect it would like to take a longer path than it had to, right?) The speed of light is the speed of light in a vacuum divided by the index of refraction. Second, the index of refraction of the atmosphere depends on atmospheric pressure and amount of water present, which change with height in the atmosphere. Therefore light actually travels on a curved path in the atmosphere from one object to another. The path goes higher than the straight-line distance in order to take advantage of the faster speed higher in the atmosphere. Because the path is so curved, the observer must always look a bit higher to see the light rays coming back down from that higher elevation. Clearly refraction must depend on some power of the distance. If you are observing something close by, light can't get to you any quicker by travelling very far upward. However, if you are far away from an object, light can take advantage of the faster speed at higher elevation and deviate more significantly from a straight line. Astraightforward calculation gives the following formula for the angular change with distance due to refraction between the observer at elevation Zo (measured in km) who also is observing a peak at elevation Zo: theta = [ 1.6 * c / { 2*(1+a) } ] * d where d is the distance in miles, theta is in radians, and a = 2.9e-4 * exp(-Zo/10 km) / (1 + 2.9 * To / 760) b = 2.9 * alpha / {760 * (1 + 2.9 * To / 760) } c = a * (b - 1/10 km) alpha = 6.5° C. / km The calculation assumes an atmosphere whose pressure, temperature (To in Celsius) and water content only varies with elevation, and an atmosphere whose temperature varies with elevation with the slope -alpha. (Alpha is defined as the rate of temperature drop with altitude, and so is positive in the above formulae in the normal case where the temperature drops with altitude.) "exp" is the exponential function. Note that this calculation assumes quite a bit. The real atmosphere can vary markedly horizontally, can have temperature inversions, can change its humidity, and have additional components like dust that change the index of refraction. The observer and observed peak are not always at the same elevation assumed in the derivation of this formula. Hence there are no guarantees that this formula will always give accurate results. However, on average, this formula probably gives the correct average answer. The results of this formula at sea level are given in surveying books as the proper term to use. The book Elementary Surveying gives the equivalent formula in terms of the "elevation loss" in feet of the observed object with distance: elevation loss = 0.574 * d^2, which is said to apply to near horizontal shots. What the book doesn't say is that this formula is only correct near sea level. The elevation loss formula consists of two terms: The curvature of the Earth term, with coefficient 0.662 ( = 5280 / (2 * R) = 5280 / (2*3986) = 0.662). The 5280 converts the final units in the above formula to feet. The atmospheric refraction term, which is therefore taken to have a coefficient of 0.574 - 0.662 = -0.088. The formula above gives a coefficient of 0.088 at an elevation of 0' and a temperature of 65° F. However, the coefficient varies markedly with temperature and elevation. If you've read this far, then you also know that the density of the water has a great deal to do with the light angle of refraction. However, the density of the author of this question is beyond any possible scientific measurement. Gone Angling wrote: I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
#5
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Whew !!!!!
-- Jerry Barton www.jerrys-world.com "Fritz Nordengren" wrote in message news:ChPqb.139951$e01.468128@attbi_s02... This is a good topic and I'm glad you brought it up. When you consider the light refraction coefficient of the gradients, the first thought would be a blue grey, but clearly once you run the numbers, you see quickly why that is wrong. In the CRC Handbook of Chemistry & Physics, page E-224 in my 56th Edition, I find the following formulae: (n-1) *10^7 = const1 + const2 / lambda^2 + const3 / lambda^4 where n is the required refractive index lambda is the wavelength in micron (millionths of a metre -- in the actual printed formula there are additional factors of 10^8 & 10^16 to cope with the fact that visible spectral wavelengths are usually quoted in Aangstroem) The values of the three constants in dry air at a pressure of 1 atm are const1 const2 const3 30 deg C 2589.72 12.259 0.2576 15 deg C 2726.43 12.288 0.3555 0 deg C 2875.66 13.412 0.3777 A correction is given in the source to allow for air which has a water vapour content. To a first approximation, the variation of the refractive index with temperature and pressure can be attributed to changes in gas density, and the gas density can be obtained from the ideal gas equation: (n-1) proportional to m/V = pM/RT. But that is just a first approximation, that does not hold up for more precise work. Atmospheric refraction slightly increases the observed elevation angle of a peak relative to the observer. The effect is actually quite complicated, since it depends on the precise atmospheric conditions, including atmospheric pressure, temperature, and water vapor content, and thus varies with time and the altitudes of the observer and the observed peak. Fortunately, the effect of refraction is less than ~15% of the effect due to the curvature of the Earth, and typically only increases the observed elevation angle by less than 0.1°. Refraction is caused by two effects. First, light likes to travel on the path that gets to the observer in the minimum time. (Light is, after all, the fastest thing in the Universe, so you wouldn't expect it would like to take a longer path than it had to, right?) The speed of light is the speed of light in a vacuum divided by the index of refraction. Second, the index of refraction of the atmosphere depends on atmospheric pressure and amount of water present, which change with height in the atmosphere. Therefore light actually travels on a curved path in the atmosphere from one object to another. The path goes higher than the straight-line distance in order to take advantage of the faster speed higher in the atmosphere. Because the path is so curved, the observer must always look a bit higher to see the light rays coming back down from that higher elevation. Clearly refraction must depend on some power of the distance. If you are observing something close by, light can't get to you any quicker by travelling very far upward. However, if you are far away from an object, light can take advantage of the faster speed at higher elevation and deviate more significantly from a straight line. Astraightforward calculation gives the following formula for the angular change with distance due to refraction between the observer at elevation Zo (measured in km) who also is observing a peak at elevation Zo: theta = [ 1.6 * c / { 2*(1+a) } ] * d where d is the distance in miles, theta is in radians, and a = 2.9e-4 * exp(-Zo/10 km) / (1 + 2.9 * To / 760) b = 2.9 * alpha / {760 * (1 + 2.9 * To / 760) } c = a * (b - 1/10 km) alpha = 6.5° C. / km The calculation assumes an atmosphere whose pressure, temperature (To in Celsius) and water content only varies with elevation, and an atmosphere whose temperature varies with elevation with the slope -alpha. (Alpha is defined as the rate of temperature drop with altitude, and so is positive in the above formulae in the normal case where the temperature drops with altitude.) "exp" is the exponential function. Note that this calculation assumes quite a bit. The real atmosphere can vary markedly horizontally, can have temperature inversions, can change its humidity, and have additional components like dust that change the index of refraction. The observer and observed peak are not always at the same elevation assumed in the derivation of this formula. Hence there are no guarantees that this formula will always give accurate results. However, on average, this formula probably gives the correct average answer. The results of this formula at sea level are given in surveying books as the proper term to use. The book Elementary Surveying gives the equivalent formula in terms of the "elevation loss" in feet of the observed object with distance: elevation loss = 0.574 * d^2, which is said to apply to near horizontal shots. What the book doesn't say is that this formula is only correct near sea level. The elevation loss formula consists of two terms: The curvature of the Earth term, with coefficient 0.662 ( = 5280 / (2 * R) = 5280 / (2*3986) = 0.662). The 5280 converts the final units in the above formula to feet. The atmospheric refraction term, which is therefore taken to have a coefficient of 0.574 - 0.662 = -0.088. The formula above gives a coefficient of 0.088 at an elevation of 0' and a temperature of 65° F. However, the coefficient varies markedly with temperature and elevation. If you've read this far, then you also know that the density of the water has a great deal to do with the light angle of refraction. However, the density of the author of this question is beyond any possible scientific measurement. Gone Angling wrote: I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
#6
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In the CRC Handbook of Chemistry & Physics, page E-224 in my 56th
Edition, I find the following formulae: (n-1) *10^7 =3D const1 + const2 / lambda^2 + const3 / lambda^4 where n is the required refractive index lambda is the wavelength in micron ......snip.... =A0 =A0 =A0 =A0 =A0 =A0 =A0 2726.43 =A0 =A0 =A0 =A0 12.288 =A0 =A0 =A0 =A0 0.3555 0 deg C =A0 =A0 =A0 =A0 2875.66 =A0 =A0 =A0 =A0 13.412 =A0 =A0 =A0 =A0 0.3777 Huh? Lmao |
#7
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LMAO
"J Buck" wrote in message ... In the CRC Handbook of Chemistry & Physics, page E-224 in my 56th Edition, I find the following formulae: (n-1) *10^7 = const1 + const2 / lambda^2 + const3 / lambda^4 where n is the required refractive index lambda is the wavelength in micron ......snip.... 2726.43 12.288 0.3555 0 deg C 2875.66 13.412 0.3777 Huh? Lmao |
#8
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Fritz Nordengren wrote:
This is a good topic and I'm glad you brought it up. When you consider the light refraction coefficient of the gradients, the first thought would be a blue grey, but clearly once you run the numbers, you see quickly why that is wrong. analysis snipped So it would be sky blue then ? ;-) -- Ken Fortenberry |
#9
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Aint sure what I just read but it sounds like the motto: If ya can't dazzle
em with brilliance, baffle em with bull****. ![]() to read Aramic. ![]() ![]() "Fritz Nordengren" wrote in message news:ChPqb.139951$e01.468128@attbi_s02... This is a good topic and I'm glad you brought it up. When you consider the light refraction coefficient of the gradients, the first thought would be a blue grey, but clearly once you run the numbers, you see quickly why that is wrong. In the CRC Handbook of Chemistry & Physics, page E-224 in my 56th Edition, I find the following formulae: (n-1) *10^7 = const1 + const2 / lambda^2 + const3 / lambda^4 where n is the required refractive index lambda is the wavelength in micron (millionths of a metre -- in the actual printed formula there are additional factors of 10^8 & 10^16 to cope with the fact that visible spectral wavelengths are usually quoted in Aangstroem) The values of the three constants in dry air at a pressure of 1 atm are const1 const2 const3 30 deg C 2589.72 12.259 0.2576 15 deg C 2726.43 12.288 0.3555 0 deg C 2875.66 13.412 0.3777 A correction is given in the source to allow for air which has a water vapour content. To a first approximation, the variation of the refractive index with temperature and pressure can be attributed to changes in gas density, and the gas density can be obtained from the ideal gas equation: (n-1) proportional to m/V = pM/RT. But that is just a first approximation, that does not hold up for more precise work. Atmospheric refraction slightly increases the observed elevation angle of a peak relative to the observer. The effect is actually quite complicated, since it depends on the precise atmospheric conditions, including atmospheric pressure, temperature, and water vapor content, and thus varies with time and the altitudes of the observer and the observed peak. Fortunately, the effect of refraction is less than ~15% of the effect due to the curvature of the Earth, and typically only increases the observed elevation angle by less than 0.1°. Refraction is caused by two effects. First, light likes to travel on the path that gets to the observer in the minimum time. (Light is, after all, the fastest thing in the Universe, so you wouldn't expect it would like to take a longer path than it had to, right?) The speed of light is the speed of light in a vacuum divided by the index of refraction. Second, the index of refraction of the atmosphere depends on atmospheric pressure and amount of water present, which change with height in the atmosphere. Therefore light actually travels on a curved path in the atmosphere from one object to another. The path goes higher than the straight-line distance in order to take advantage of the faster speed higher in the atmosphere. Because the path is so curved, the observer must always look a bit higher to see the light rays coming back down from that higher elevation. Clearly refraction must depend on some power of the distance. If you are observing something close by, light can't get to you any quicker by travelling very far upward. However, if you are far away from an object, light can take advantage of the faster speed at higher elevation and deviate more significantly from a straight line. Astraightforward calculation gives the following formula for the angular change with distance due to refraction between the observer at elevation Zo (measured in km) who also is observing a peak at elevation Zo: theta = [ 1.6 * c / { 2*(1+a) } ] * d where d is the distance in miles, theta is in radians, and a = 2.9e-4 * exp(-Zo/10 km) / (1 + 2.9 * To / 760) b = 2.9 * alpha / {760 * (1 + 2.9 * To / 760) } c = a * (b - 1/10 km) alpha = 6.5° C. / km The calculation assumes an atmosphere whose pressure, temperature (To in Celsius) and water content only varies with elevation, and an atmosphere whose temperature varies with elevation with the slope -alpha. (Alpha is defined as the rate of temperature drop with altitude, and so is positive in the above formulae in the normal case where the temperature drops with altitude.) "exp" is the exponential function. Note that this calculation assumes quite a bit. The real atmosphere can vary markedly horizontally, can have temperature inversions, can change its humidity, and have additional components like dust that change the index of refraction. The observer and observed peak are not always at the same elevation assumed in the derivation of this formula. Hence there are no guarantees that this formula will always give accurate results. However, on average, this formula probably gives the correct average answer. The results of this formula at sea level are given in surveying books as the proper term to use. The book Elementary Surveying gives the equivalent formula in terms of the "elevation loss" in feet of the observed object with distance: elevation loss = 0.574 * d^2, which is said to apply to near horizontal shots. What the book doesn't say is that this formula is only correct near sea level. The elevation loss formula consists of two terms: The curvature of the Earth term, with coefficient 0.662 ( = 5280 / (2 * R) = 5280 / (2*3986) = 0.662). The 5280 converts the final units in the above formula to feet. The atmospheric refraction term, which is therefore taken to have a coefficient of 0.574 - 0.662 = -0.088. The formula above gives a coefficient of 0.088 at an elevation of 0' and a temperature of 65° F. However, the coefficient varies markedly with temperature and elevation. If you've read this far, then you also know that the density of the water has a great deal to do with the light angle of refraction. However, the density of the author of this question is beyond any possible scientific measurement. Gone Angling wrote: I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
#10
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![]() Melt fluorocarbon line in a glue gun and smear it all over da boat. Fish can't see ya commin dat way. Optimum water refectory color dats what fluorocarbon can do for ya. "Gone Angling" wrote in message ... I'm planning on building a cajun sneak boat. I want to use it for a fishing situation in a small shallow bay. What is the optimal colour to paint the submerged portion so it doesn't scare the fish ? It's a nice starter project. |
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