Reply With QuoteGreat pics. Thanks for posting
Had to go to river town section yesterday to reset sounder settings after putting in new software.
We' starting to come up to threadfin time in the Fitzroy.
While adjusting sounder, found some threadies that had arrived overnight and got some sounder screenshots.
Small fish are herring/yorkies that threadies are following.
Mid-sized fish are blue threadies and larger ones sprinkled through the schools are king threadies (up to 80 - 90 cm.
The screenshots are only part of the visitor numbers. Couple of thousand of them, I reckon.
Other screenshot shows value of s/scan. Image reflection doesn't show much except that its a fish but the shadow sure gives it away close to the bottom about 6m away on RHS.
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Great pics. Thanks for posting
Yeah awesome pics...keep em coming please.... I''m still trying to learn how to use the features on my new sonar....
How good is that fish image..looks more like a barra than a threadie though..
Also thanks for the post Mate though im a tad south of you by aprox 100 odd clicks , the top downscan pic looks like a school of yorkies /herring unless mistaken ?? can see theone that looks like a barra onits own and then on the sidescan Pics looks like heaps of Fish . How do you define them as Threadies ??, just by experience ??..
Could that.one possibly be a mangrove jack?Attachment 121219
Sent from my SM-G900I using Ausfish mobile app
Yep, Disorderly.
Its a barra of 90cm. I pulled up and cast a fluro red/green shallow diver at it. On the 4th cast he picked it up. Nearly sight fishing. Was copybook stuff but usually not that easy.
Volvo, yep the little guys are herring/yorkies alright. Heaps of them. This time of year they come up river and small sized threadies follow them. When the prawns also arrive (not here yet) bigger king threadies follow up to about 110cm or so.
Usually zoom in to look for forked tail on the shadow on blues and small king. Here's one that I didn't even have to zoom on to identify. 5m on LHS, nearly on bottom and back behind boat. Bit bigger than a yorkey.
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Don't seem to get big king threadies far up river. They tend to stay further down where the big prawn schools hang out.
My pb king is 139cm to end of tail. A few times.
But gee, there are some big buggers. In a strong run one day, I couldn't reach the botton in 6m of water with a 20g thready buster (yep, I'm a tragic of Rob Stevens). Didn't have any heavier ones so I put 2 thready-busters on (40g) together. Reached the bottom ok then.
Got 3 king up to 139cm on that rig with 80lb leader.
4th hookup took the leader and both thready-busters. Gets expensive at 2 soft vibes at a time. Big king that one. A big king will pull a big barra backwards any day.
Been some really big ones in recent times. I'll put a couple together if you like plus some some sidescan shots.
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Sorry gazza. Didn't see yr question in there.
It's a barra. We don't usually get mangrove jack in the river except sometimes up in the rockbars in the town reach . They're mainly in the cleaner creeks feeding onto beaches/headlands. But we do get fingermark/golden snapper which are of the same family as mangrove jack and new guinea black bass.
I've only ever caught 1 mangrove jack (by accident) of 215mm. Brother has bigger in his fish tank.
Couple of photos of big king all over 140cm with fish on left at 166cm plus a screenshot of big king on bottom on s/scan down the river (mate's helix 9).
Largest king I know of from the river is 170cm. Got a photo somewhere.
King are what's known as "ram feeders" and barra are "suction feeders".
King usually pick up food on their way through with mouth and gills open (unless foraging with whiskers in mud shallows for prawns).
Barra "suck it in" and always turn away a split second after they do it.
So a barra strike is a real hard jolt and a hard run but always fought at near range (max 30m or so).
King just pick it up and run so the battle is then a long distance one in strong run (could be up to 100m away) so you need plenty of line. But they don't give ground easily. Barra (even big ones) will suddenly run out of puff and give up. King fight all the way.
Thanks for sharing mate , VERY NICE Kings there fer sure ..What sounder you using if you dont mind my asking??.
Some great image's there
Sent from my SM-G900I using Ausfish mobile app
Humingbird OffcourseOriginally Posted by Volvo
Thanks for sharing mate , VERY NICE Kings there fer sure ..What sounder you using if you dont mind my asking..
thanks for sharing awesome shots, side scan etc is still bamboozling a bit .
crazy how you can identify the fish by the detail of its tail shape crazy
Seems like magic doesn't it? But its not.
Its simply having an understanding of the fundamentals of sounders but you don't have to know the "ins and outs of a duck's b.." about it.
Just look at post #6 image again. The big king nearly on the bottom back behind the boat.
Look at the top LH image box.
The images have all scrolled past the king (as has the boat). Look at the current water depth display of 2.5 metres. Back where that king was it was 2 metres (follow the bottom outline back in that top LH box).
Remember that a conventional downward looking sounder beam is like an upside-down ice cream cone with the narrow pointed tip originating at our transducer.
At a distance of 2m from the boat in a downward direction, the big rounded end of that beam has not expanded enough to pick up that king even though its not far off boat centreline. So it simply doesn't show up.
Ditto with the other box underneath the downscan box. That's the normal sonar beam.
Basically what's happening is that we are looking at the bottom through a straw and at 2 metres, and we aren't going to see much of the bottom. So we won't see any images even though they may be close by.
The side-scan beam off to the left is about 80 degrees wide and vertical in shape so we'll see everything out wider. THAT'S why we could see the king easily. Without the advantage of that wider angle beam, we wouldn't have known that the king was even there.
In relation to the ability to see such detail as the clear image of the tail, we can thank the scan frequency in use for that. The higher the frequency in use the better the "image resolution" that we can see. In the case of this sounder's frequency kit, the freq in use is what Hummingbird call Mega(1.2 megahertz - 1,200 kilohertz).
That Mega frequency allows us to see targets (fish) down to 1.2mm long. That's why the smaller fish (herrings and yorkies) showed up as individual fish and not simply as "bait balls". II agree with Volvo's observation. Need to be able to recognise what you see knowing the capabilities of what you're using.
The reality is that we DON"T need to see fish that long, but we DO need the clarity of detail when looking at parts of bigger fish such as the detailed shape of the tail (forked one) or the body shape (barra).
eg Gazza asked if the barra image in post #4 could be a mangrove jack. He's right. It could be but the MJ don't have as big a body hump at the forehead as a barra PLUS we don't get MJ in that neck of the woods. Gazza didn't know that so he's right. Its got a shape pretty close to that of a MJ.
As far as being able to see that king so close to the bottom we can thank the CHIRP technology.
CHIRP gives us the ability to distinguish between target close together that would normally show up as 1 single indistinguishable single "blob" without a clear shape. Or simply like part of the bottom.<br>
THAT'S called "range resolution" and is dependent on how hard the CHIRP function is being driven. THAT'S normally set by the sounder so we don't have to be a rocket scientist or anything to use a CHIRP sounder. Even I can use one and I'm not the sharpest knife in the drawer.
Does anybody want to see some stuff that I've learned about the basics of sounders over the years? Words of one syllable stuff about the very basics and NOT knob-twiddling stuff that one normally comes across.
If so, just yell out.
Yourve done a GREAT job of explanation so far mate so ill put the finger up and say PLEASE Do
image S00082.jpg ,looking at top far left think it appears to say 15 mtrs ?? are they fish along there or just part of the bottom structure that appear as smallish humps??..
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