how to use temperature breaks

[Lil John]

A rookie question here about temperature breaks and how to use them and fish them to your advantage. My local waters here in Guam are in the low-mid 80's year-round. The water cools to about 82 degrees from about now till April then goes up to around 84-86 the rest of the year. Like other bodies of water around the world, we do get temperature variations off-shore but I think they are just not quite as extremem as in other locations. My NAVMAN TF6600 has an alarm I can set which will beep when I hit a temperature variance of any level (I can set the "sensitivity" of the alarm -- or what level of temperature variance will activate the alarm down to increments of 1 degree variance).

SO....armed with all this "technology", and with Wahoo starting to come in, I want to use it to my advantage in identifying temperature breaks. I do wonder though that since the transducer temperature sensor is measuring surface temps, are variances here as significant to fish catching as variances deeper in the water column. I realize that temperature breaks in my part of the world may not have as big of an effect on fish catching as in other parts of the world.

With all of this in mind, what level in temperature variation should I set my alarm for and be looking for? Once I hit a break, how do I "work" that area trolling surface lures?

[twotems]

We have similar conditions here too and I've never felt temp. breaks as such apply much in the tropics. I think temperature in itself is important here though. I've found anything above 85 doesn't really produce Tuna. But it's great for Billfish and Dorado. I may be wrong and I'm certainly no expert. My 2 cents.

[Tireless]

In the spring in N Ga waters we often have 5 degree temp breaks that form noticeable rips on the surface. The rips tend to stack up bait and sea grass...which tend to stack up predators lurking below. I have fished on both sides of the rips so I do not have an opinion on which side is more productive.....I just know that .......... rip + cont. shelf = big fishies.

[brdawg2001]

I fish the same area as Tireless....I use my eyes more than anything to spot the rips....troll parallel and cross over occassionally to see which side is working....

r

[twotems]

We have a distinctive "line" (I guess what you guys call a rip) between green inshore water and blue ocean water that can be from 5 to 35 miles out. The blue side holds the big fishies. Like Tireless says, the closer that line is to the continental shelf (19 miles here) the better the fishing.

[Bullshipper]

The division between clean blue water and green is not a rip, but you will find that the blue water is a little cooler, oxegen rich and productive.

If there is no structure in your area or strong tidal currents to cause vertical shear, than you will probably have to use your fish finder to locate horizontal rips where layers of oxygen rich waters lie below more static warm water. Colder water is denser than warm and you will see a cloudy area under the clear, where downriggers help when the water turns hot.

But it you have bathometric charts to start to look for structures this will help to find where current lines are there strongest and easiest to spot, and they are always more productive that just sight trolling looking for fins.

[Lil John]

Thanks guys, I do appreciate the input for sure. BULLSHIPPER: as you know, Wahoo are kinda difficult to spot on sonar so basically all I use my sonar for this time of year (aside from confirming dropoffs shown on the plotter) is to "look" 100' down for bait schools. Your recommendation to use the sonar to find horizontal rips is interesting. If I were to do this, how far down should I be searching (with the sonar). Right now when I am out in 5,000-9,000ft of water working FAD's I only use manual range to 100' (again,only looking for bait fairly close to the surface). Are you suggesting I set manual range much deeper (say 500ft or more) and "look" for cooler water lines? If so, how does a horizontal sheer of cooler water "look" on a sonar display? THANKS!

[ubettcha13]

horizontal sheer I beleive is called a thermocline out here on this coast should show up as a line in your screen

[Tireless]

If you can tune your sonar you can dial in a thermocline......I think it has to do with the cooler water being more dense and it shows up as you increase the gain. My old $135 Garmin FF used to show that automatically.

[Lil John]

When manually "tuning" sonar, you have two MAIN settings: gain and sensitivity. When you are out in the deep (3,000ft+ with no bottom) and you keep turing your gain up, eventually it will register constant noise. How do I see the thermocline then?

[257 CC]

what we always do is troll the actual break in the temp and thats where we always catch sails dolphin and sometimes tuna but mostly bills and countefits soo