Sounder pics - what's your thoughts
Hi all
Went out today with my daughter for a dive, hoping to snare a few crays. Headed out from The Cut but the conditions on the water mirrored the forecast on seabreeze....bugger. The swell was quite big and the water in close was dirty and churned up so we decided against going in.
Decided to sound around and check out some possible new dive sites and came across a patch of ground that gave up these pics. To me, they look like caves and overhangs....just wondering what you guys make of them. *Sorry about the quality of the pics...it was a bit rough out there today.
I'm pretty keen to have a dive on the site when the water clears up a bit...when I do, I'll take some underwater pics for comparison.
The weather looks pretty good next Tuesday and Wednesday....fingers crossed!
Have a great Christmas and enjoy the time with your families.
regards
rusty...
If life is boring, you must be doing it wrong!
till
Posts: 9358
Date Joined: 21/02/08
I'm sure there are a few
I'm sure there are a few crays in there for ya!
Ryan Thipthorp (not verified)
Posts: 16
Date Joined: 01/01/70
sounder pics!
To me, they look like caves and overhangs....just wondering what you guys make of them
Spot on Rusty............hidey-holes for crays!
smash
Posts: 434
Date Joined: 01/12/10
while there maybe caves
while there maybe caves and/or overhangs I doubt your sounder shows them as such.
For these pictures to be showing that it would have to have penetrated 2 meters of solid rock, and then again on the bottom of the cave.
Id actually guess at a limestone bottom sloping into the sand/mud. The sounder may be penetrating the sand/silt as it is much easier due to being waterlogged.
If you drive over it again adjust your gain and other settings to see if you get a different show on the upper layer.
For it to be a cave the top layer MUST be solid rock and you would see a colour difference between the upper and lower layers when adjusted.
fishy fingers
Posts: 1719
Date Joined: 28/04/07
I agree with you
and I've said it before although I'm not an expert on sounder technology I do understand the basic operation and for the sonar to penetrate the solid rock (cave roof) hit the bottom and bounce back to the transducer (back through the cave roof) to show a cave does not seem possible to me and there are plenty of people out there that think the same.....having said that plenty believe they can show cave too.
sunshine
Posts: 2627
Date Joined: 03/03/09
Definitely caves and overhangs
But for goodness sake turn the auto gain off and go to manual and back it off and those ledges and caves / overhangs will be far clearer
When used correctly can find you some speccy dive sites - I use mine to drop the pick just over the edge of ledges like that to ensure easy release and makes diving a breeze as it takes you right into prime territory.. .............great for prospecting new sites when conditions are shitty
Ryan Thipthorp (not verified)
Posts: 16
Date Joined: 01/01/70
guaranteed!
Your Furuno sounder pics are caves & overhangs for sure Rusty!
Sunshine is spot on with getting rid of auto gain .......... manual everything as you need to fine tune your Furuno sounder to make everything sharp.......dont allow the unit to auto dictate!
meglodon
Posts: 5981
Date Joined: 17/06/10
caves and sounder pics
When you get the chance it would be interesting to see just what the bottom is like if you get afew photos.
All the best for christmas to you and yours
r.gates
Posts: 573
Date Joined: 15/11/10
Sounder pics
Thanks guys for your comments.
We're heading out on Wednesday for a dive so I'll be sure to sound over the area with the sounder on Manual, just for comparison, and I'll take some photos from underwater. I do hope there are some caves with crays in them....the hard part (for me) will be snaring the little buggers!!
regards
rusty...
If life is boring, you must be doing it wrong!
grayzeee
Posts: 2283
Date Joined: 09/07/09
ledges and overhangs.there's
ledges and overhangs.
there's already been a post on this with pics to prove.
you can see two bottom returns meaning the unit is reading the top of the reef and the ground next to the reef at once. (both area's covered by beam)
If I spent half as long fishing , as I do reading this bloody forum , I'd be twice the fisherman I am.
Ryan Thipthorp (not verified)
Posts: 16
Date Joined: 01/01/70
Caves & overhangs .......easy to see!
Previous Thread!
http://fishwrecked.com/forum/how-can-i-catch-my-first-dhufish
sarcasm0
Posts: 1396
Date Joined: 25/06/09
Geez I wish I read that at the time
I used to work transcribing Geophysical Seismic Data from magnetic tape to digital data sets. Whole Terrestrial and marine survey data sets for Oil and gas, Mining etc which really are just millions of individual 2d sounder shots stitched together with software to create a 3d perspective.
The comments 'it's a matter of physics - can sound waves "penetrate" structure, and "read" "sub-surface" structure (ie. displaying a cave or void)???? I don't think so' and 'if you understood "the physics of the sounder operation"' are just mind boggling.
r.gates
Posts: 573
Date Joined: 15/11/10
Submersible camera
Thanks guys for all your comments. The thread that Ryan posted the link to, was a very interesting read.
One of the reasons why I bought the submersible camera was to try to understand what my sounder was showing me.
When we fished the Bouvards a few times recently and caught some skippy, the images on the sounder looked like 'caves' to me, and when we dived on one of those spots a couple of weeks ago, I was amazed at the number of caves, ledges and swim throughs that we came across....not too many crays though, unfortunately.
The more we use our equipment, the more knowledge we gain, and with the help of others here and elsewhere, the better armed we are at catching our elusive prey.
We never stop learning!
regards
rusty...
If life is boring, you must be doing it wrong!
Paul G
Posts: 5215
Date Joined: 12/12/07
Yep no way you can pick up
Yep no way you can pick up caves and edges just can't be done I think you should all throw your sounders over the side.
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Paul G
Posts: 5215
Date Joined: 12/12/07
http://fishwrecked.com/forum/
http://fishwrecked.com/forum/40m-dive-today-sounder-pics. Check this out looks the same to me.
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Ryan Thipthorp (not verified)
Posts: 16
Date Joined: 01/01/70
ha ha
But it cant be true lol ......... good link there Paul to show people sounders do read caves & ledges etc
fishy fingers
Posts: 1719
Date Joined: 28/04/07
not a cave though is it?
My definition of a cave must be different to others as I dont call an overhang a cave or a ledge for that matter
pauls pic there is far from a cave but given the sound waves come down in a cone shape and bounce around then it's possible to pick
up an overhang I accept that but not caves
shabba
Posts: 484
Date Joined: 26/02/08
ive been diving with Ryan and
ive been diving with Ryan and his furuno is showin caves n ledges we hit the bottom and yeh its exactly what we saw
Paul G
Posts: 5215
Date Joined: 12/12/07
Sorry but I will get a
Sorry but I will get a sounding of a cave for you I have sounded over the shark cave at rot to and no way you can miss that as a cave.there is a pick on that link showing the opening to a large cave
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