It's difficult LMB fishing here (North). The season here is truncated due to weather AND regulations. No pre-spawn or spawn/bed fishing, season not open until last week of June, etc

 

Therefore, I want to maximize my time in likely fish holding areas. Local advice has always seemed lacking and unreliable. I solidly fished an area today that was supposed to be "loaded" and not a single bite. So I want to rely on myself to find high percentage areas. And I think bathymetric maps can be a useful starting point tool here. And so I am endeavoring to do this.

 

Part 1 was choosing my app. After much back and forth, I settled on Navionics. I also liked that they had a Fishing Ranges feature to customize the maps shading with user defined color and depth ranges. And that's what I'm asking advice for here. So this is Part 2

 

I understand the importance of setting custom colors. The most obvious being it allows quick initial identification of potential fishing spots. But I'm coming up a bit empty in my research for HOW and WHY to assign what colors to what depth ranges so you can arrive at the best result.

 

For example, the maximum depth for me would be 30 feet. How do I set up the graduations? Every 2 feet? Every 3 feet? More? And I presume Red for shallowest, then orange, then yellow....then what? 

 

I am really quite curious what has worked for you and your eyes.

 

Any advice on your set up or good, very specific videos on the topic? 

 

 

Topo maps, right?

Colors distract me.  I have gotten away from them mostly.  Only time they are helpful to me is hazards to navigation, humps, shoals, bars, timber, etc.

I get more value from studying distance between gradient lines in a spot/area.  5 foot lines are OK when starting out with a large body of water.  Zooming in, go to 2 or 3.... whatever offers info without clutter in your mind.  

Color is just preference.  My maps on my FF units are set up in shades of blue because it works for me.  Then I highlight depth ranges with other colors.  For example, on Wednesday I knew I wanted to concentrate on 20-40' because 0-20' is heavy standing timber and deeper than 40' is a pain to fish.  I was looking for isolated cover.  I set the map to shade 0-20 with red because I didn't want to be in there and 20-40' with green so that it showed up clearly against the blue.  Your eyes might be different, so the only thing you can do is play around with your settings and seew what looks best.

 

As to gradation, I want 1' increments.  Below is an example from Navionics online and I swapped between sonar chart and nautical chart so it is an extreme example (20' vs 2' increments) but in the first picture all you can tell is that deeper water swings closer to the bank, maybe following the cove's contour.  In the second, you can clearly see the flat in 12-15' and how the bank on the northwest side is decently steep while on the southeast side is more gradual.  If you're doing map study to check out locations, that would be a pretty solid place to check out in the pre-spawn and even summer depending on the lake and what the fish are doing.  Sometimes the difference of 1' or 2' is all the fish need to gather in a spot so I want the map to show as much of that detail as possible.

 

Incidentally, the example below is a place where mapping can also fail or mislead you.  I'm not sure of the source data that navionics uses, but if you look at the third picture it looks like there is an island with super shallow water between it and shore (like a swamp or bog) just down the shoreline from the first two pictures.  The map data says it is super shallow along the shoreline northwest of the island which is what rounds out that point/shallows going into the cove in the second picture.  However, that's a figment of navionics interpolating the data from a bad set of data.  In reality, the water is ~15' between the island and shoreline and that continues all the way down parallel with the bank.  So it is a much steeper bank than the map indicates and you can only know that by going and looking at it.  The flat is still there but the detail around it isn't what is on the map.  

 

 

 

 

My lake has a mapped island like the above.  I avoided the 'shallow narrows' for a couple years, and never saw anyone fishing there.  But last fall, I graphed it all and found a really nice cut that regularly holds fish.

10 minutes ago, Choporoz said:

My lake has a mapped island like the above.  I avoided the 'shallow narrows' for a couple years, and never saw anyone fishing there.  But last fall, I graphed it all and found a really nice cut that regularly holds fish.

 

This is a huge problem for satellite generated bathymetric images. They are NOT accurate. There are no satellites that I know of that can "read" the bottom contour through the water. So what they come up with does not always match reality.

 

I gave up on satellite bathymetry years ago.

 

As you have discovered hands on mapping is the most accurate best way to go.

1 hour ago, Choporoz said:

My lake has a mapped island like the above.  I avoided the 'shallow narrows' for a couple years, and never saw anyone fishing there.  But last fall, I graphed it all and found a really nice cut that regularly holds fish.

 

I wish that was the case here.  the island is a steep sand/silt bank and the main shoreline is a steep cliff type bank.  I've fished through it multiple times, run FFS through it, etc.  Not a fish.  When the water was 10' low the first time I took the kayak through it to see what was there and it is just a featureless U shape with nothing interesting.  BUT, the only way to know is to run through it with your own electronics.

Typical holding areas for LMB should have some form of cover along with the structure elements. Aquatic plants can’t grow in sand or clay (very fine sand) and on rocks, they need soil to root in. Can’t “see” aquatic growth using sonar maps, overhead satellite imaging you see it and on the water sonar use.

What structure elements I look for;

Long under water main lake points, easy to find.

Saddles connecting connecting humps ( underwater islands). The best saddles are perpendicular to the wind or current. These are funnel zones.

Steep bank or river channels that drop off to a small flat area then continue dropping. The flat can be table size as long as it is at the right depth*.

*Right depth is the life zone where baitfish are located above the thermocline depth.

Master those few structure elements then learn isolated structure on structure like boulders and will find the bass you are looking for.

Tom

 

It should have a default couple of color palettes, just use one of those, whatever lets your brain see the lake. 

 

With one exception - you can often figure out that you want to target a certain depth, either because of the depth you saw bait or where the thermocline is. You can set a highlight color on that depth and zoom out a little and use it to look for good structure that intersects that depth. 

2 hours ago, WRB-2.0 said:

Typical holding areas for LMB should have some form of cover along with the structure elements. Aquatic plants can’t grow in sand or clay (very fine sand) and on rocks, they need soil to root in. Can’t “see” aquatic growth using sonar maps, overhead satellite imaging you see it and on the water sonar use.

What structure elements I look for;

Long under water main lake points, easy to find.

Saddles connecting connecting humps ( underwater islands). The best saddles are perpendicular to the wind or current. These are funnel zones.

Steep bank or river channels that drop off to a small flat area then continue dropping. The flat can be table size as long as it is at the right depth*.

*Right depth is the life zone where baitfish are located above the thermocline depth.

Master those few structure elements then learn isolated structure on structure like boulders and will find the bass you are looking for.

Tom

 

I do all of that and still come up empty. I've even gotten very specific advice from "experts" on my local maps (they circled areas...which were largely the same as areas I picked out) and came up empty. Regardless of what bait was thrown, what weather, time of day, etc

 

And I'm not the only one. Ran into some guys from down South USA and they said if they had to fish LMB like here, they'd quit! LOL 😆  SMB on the other hand are easy here (best SMB fishing in their lives according to the same guys).

 

It's just really tough here and the norms and "rules" don't seem to apply quite as readily as in other areas..particularly those down south.

If you lakes have Pike and Musky they are the top predators and take over the prime areas. LMB if that scenario tends to to locate inside weed line areas, tight o cover.

Tom