# Identifying Blue Water



## FISH ON ! (May 18, 2014)

What image/s best depict blue water? True color is so often obscured by clouds and/or the resolution is so poor that it's hard to be sure, it seems to me. Is Chlorophyll a dependable indicator?

And pardon the ignorance…but WTHeck is a rip? Can someone post some pictures or a link to pictures? I'm thinking it is adjoining water is moving in different directions or speeds and the surface will show disturbances, like slick water, ripple variances, debris might collect there etc.


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## Downtime2 (Sep 27, 2007)

Yes, chloro shot is gonna be a damn good indicator. Invest in Ripcharts, Hiltons, Roffs or one of the services that show it's location. A rip or line is caused by two different bodies of water moving against each other. Blue to green or a variation of such. You'll have opposing current and if conditions are right foam, weeds or debris. Easily identifiable.


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## jack2 (Mar 19, 2010)

yes, wade is right
when two bodies of water meet, they form something we know as a weed line with everything in the garbage to a kitchen sink (if it floats) to a beer can. sargassum, a floating macroalgae in the gulf, moves with the gulf stream and along with this weed, all of the trash that humans throw overboard . 
when two bodies of water with different temperatures meet, they form a swirling action much like a tornado. you can see the cyclonic or swirl pools where this boundary meets. the mat of debris and sargassum stops until the water temperature equalizes and the whole mess goes with the current again. this is the mahi's home. any floating objects in the ocean is the habitat. some floating objects as small as a cooler top to the famous "weed line".

jack


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## FISH ON ! (May 18, 2014)

Thanks guys! I've been using RC for several years but I've never been quite sure if the chloro was a dependable blue water indicator. As for rips, I've fished weed lines for years but just never fished with anyone who referred to them as rips. I have noticed as I'm sure you have, that there are "disturbances" on the water surface, the most obvious to me being the slick zones that meander around out there. I have often thought these or other variations in the prevailing water surface were likely caused by currents, temp changes, up/downwelling etc.


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## rustybucket (Aug 18, 2011)

FISH ON ! said:


> Thanks guys! I've been using RC for several years but I've never been quite sure if the chloro was a dependable blue water indicator. As for rips, I've fished weed lines for years but just never fished with anyone who referred to them as rips. I have noticed as I'm sure you have, that there are "disturbances" on the water surface, the most obvious to me being the slick zones that meander around out there. I have often thought these or other variations in the prevailing water surface were likely caused by currents, temp changes, up/downwelling etc.


You can actually use multiple indicators to find a water change. Salinity and Altimetry will often tell you what is going on if chloro and sst are obscured. Salinity will be clear no matter the cloud cover.

Chloro is obviously the best. Chlorophyll chart is actually looking at the algae in the water and visually represents water color. On ripcharts, blue is blue water, green is green water and red is chocolate milk. The recent granule is the best most up to date shot, but the daily composites are not too bad (composite is all the granules combined for a more complete image).

Really, in a perfect world you will use multiple indicators to verify/confirm there is a separation of two bodies of water in a certain location. In a perfect world those two bodies are literally rammed up against each other and you can easily visually see the rip/change in person. But in reality lots of the breaks are over a mile or so as the two bodies blend into each other.

Most rips have some type of weed/junk line on them, but not all weed lines are rips. The weed lines that ARE rips will almost always be more productive than those that are not on rips.

The biggest benefit to using ripcharts or hiltons or roffs is that I can almost pinpoint where a rip will be. Knowing the given area I can almost tell for certain if there will be a weedline there or not. This allows us to travel a lot at night without much concern that we will be passing over the water change. It also saves us TONS of fuel by knowing where we are going.

Also, once you get out there, having SST's on your MFD (ours is garmin) will really help you pinpoint where the water break is and what has changed since you left the dock.


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## FISH ON ! (May 18, 2014)

Thanks Rustybucket for the detail. How much SST change would indicate a change in water? I guess I’ve never watched it closely. I don’t think I’ve ever noticed more than a degree or two.


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## FleaBag (Oct 19, 2016)

altimetry..... usually the line will be around zero to a negative two. high positive numbers represent empty blue water. now would somebody please explain how a down welling is when altimetry is high and an up welling is when altimetry is low. cant wrap my head around it.


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## jack2 (Mar 19, 2010)

FleaBag said:


> altimetry..... usually the line will be around zero to a negative two. high positive numbers represent empty blue water. now would somebody please explain how a down welling is when altimetry is high and an up welling is when altimetry is low. cant wrap my head around it.


wow,
i'm a physics teacher and would hesitate to offer an explanation in a short post. tom hilton would be the best source of information. maybe he will attempt this brain-teaser.
here are just a few basics that may help that your probably already know:
1, warm water rises, cold water sinks
2, cold water has more nutrients
3, wind direction works with the earth's rotation to cause water movement causing upwelling and downwelling
4, upwelling is most beneficial (chlorophyll production by phytoplankton) to the bottom of the food chain
5, upwelling is where you'll find the most pelagics

hope this helps
jack


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## FISH ON ! (May 18, 2014)

FleaBag said:


> altimetry..... usually the line will be around zero to a negative two. high positive numbers represent empty blue water. now would somebody please explain how a down welling is when altimetry is high and an up welling is when altimetry is low. cant wrap my head around it.



Here's my take.

Altimetry is a topographic map of the water surface. Positive numbers indicate high spots, or “hills” of water. Negative numbers indicate low spots or troughs. Since water, wthhout other influence, will seek to be level, the high spots are pushing downward seeking level. The upwelling is from the low spots, which are “piling water up” where the positive contours are.

Whew! 😓


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## panhandlephinsphan (Aug 25, 2008)

So on a hilton’s Altimeters chart, the red areas are “higher” with positive numbers and not good to be in and the blue areas with lower numbers are lower and better to be in or do you want to be in the area of change in between the two?


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## jack2 (Mar 19, 2010)

panhandlephinsphan said:


> So on a hilton’s Altimeters chart, the red areas are “higher” with positive numbers and not good to be in and the blue areas with lower numbers are lower and better to be in or do you want to be in the area of change in between the two?



www.youtube.com/watch?v=6j_nCKus1l4


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## panhandlephinsphan (Aug 25, 2008)

Well that answered that! Perfect- thank you.


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