Author Topic: SI usage in shallow water (Read 30354 times)

jworks · « **on:** February 16, 2015, 11:21:27 AM »

Has anyone had real life experience with SI in shallow water? I'm talking 1 - 8 ft. I have an 899. I've been reading some posts that said for the best images make the setting 800 kHz, and range settings to no more than 2 1/2 to 5 times the depth. I mostly fly fish for bass and bluegills in water no more than 8 ft, with most of the time the fly being in 1 - 6 ft. I bought this SI unit thinking the SI would aid me in seeing bass on large shallow flats, and seeing bluegills bedded up. The suggestion "2 1/2 to 5 times depth" would mean with the boat in 6 ft of water I should set the range out to no more than from 15 - 30 ft. That's not much. So, I would like some response from people with real on-the-water experience using SI in 1 - 6 ft. Anybody got experience with this?

Humminbird_Greg · « **Reply #1 on:** February 16, 2015, 12:18:13 PM »

jworks,
In those water depths you will get better coverage with the 455kHz Si sonar as it radiates more outwards than does the 800kHz Si sonar. Fishing for Bluegill you will want a close range as they will be smaller and harder to see. Larger fish would allow for a wider Si Range setting. Ex: fishing shallows for redfish out of Buras (Louisiana) we were easily spotting them with the Si Range set to 100 feet. It isn't that the unit cannot cover a wider area, it is that you won't be able to see the sonar returns from the fish because they will be so relatively small compared to the Si Range used.

jworks · « **Reply #2 on:** February 16, 2015, 12:37:21 PM »

Gred, I'm glad you mentioned the reds at Buras !! That's one thing I've been thinking about because I'll be going there in May. I've been wondering if I could see fish in water that shallow down there. I'm not going to Buras, but to Grand Isle - fishing inland between Grand Isle and Leeville. Same thing as Buras though and all those places down there. Water is 3 ft. max. Mostly 2 ft. Or less.

Yes, I had already thought about the 455 might have to be used in water that shallow. I was glad to hear you could see the reds in water that shallow. I'm assuming you were in the marshes 1 - 3 ft deep.

Humminbird_Greg · « **Reply #3 on:** February 16, 2015, 12:41:53 PM »

Yep, in the (shallow) marshes and even some of the deeper pools and around oyster beds. They were harder to see when over the oyster beds due to the harder returns from the oysters but you could still make them out. Worked well for the specks too. I need to see about going back down there this year…

jworks · « **Reply #4 on:** February 16, 2015, 12:56:37 PM »

I'm originally from north La. but I lived in south La for 3 yrs before we moved to Alabama in '99. Caught tons of reds back in late 90s. Frankly though, I went back in Nov '13 and Oct '14 and did very very poorly. I don't know if it was the places I use to fish 15 years earlier are no longer good or what. I just don't know. Caught only 5 the first trip (3 days of fishing) and 6 or 7 the 2nd trip (7 days). That's how poorly I did. Maybe the hurricane changed up stuff. I don't know. But it all looked the same. I didn't have SI back then. I was just fishing the old way.

Gimp · « **Reply #5 on:** February 16, 2015, 04:47:36 PM »

Bluegill and bass beds show up very well in 2-8ft ( and deeper ) of water on 455kHz SI out to 80 ft to the side. I never set up the distance farther than that so it might work well even farther out. Spotting individual fish is an entirely different matter. If it's a hard bottom, say gravel, you will have to do some serious tinkering with settings and even then, those returns get awful tiny much past 20 ft in that shallow. Your mileage may vary.

jworks · « **Reply #6 on:** February 16, 2015, 05:57:52 PM »

Gimp, I've only been out with it twice because of the cold weather. So, not much time to really get use to a SI unit. First time: a lake is mostly dirt and mud bottom with some rocks here and there. Other lake is all rock bottom but very deep. I know what you mean about the rocks or gravel. They show up good when you learn what you're looking at. Fish in that environment might be hard to see. Anyway, I plan on fishing the first lake the most. Lot of shallow water there under 8 ft. But it also has loads of grass that starts coming up in mid spring. I assume the beds show up as shadows. Is that right?

kosmo · « **Reply #7 on:** February 16, 2015, 07:01:26 PM »

Quote from: Humminbird_Greg on February 16, 2015, 12:18:13 PM

jworks,
In those water depths you will get better coverage with the 455kHz Si sonar as it radiates more outwards than does the 800kHz Si sonar. Fishing for Bluegill you will want a close range as they will be smaller and harder to see. Larger fish would allow for a wider Si Range setting. Ex: fishing shallows for redfish out of Buras (Louisiana) we were easily spotting them with the Si Range set to 100 feet. It isn't that the unit cannot cover a wider area, it is that you won't be able to see the sonar returns from the fish because they will be so relatively small compared to the Si Range used.

Quote from: jworks on February 16, 2015, 11:21:27 AM

Has anyone had real life experience with SI in shallow water? I'm talking 1 - 8 ft. I have an 899. I've been reading some posts that said for the best images make the setting 800 kHz, and range settings to no more than 2 1/2 to 5 times the depth. I mostly fly fish for bass and bluegills in water no more than 8 ft, with most of the time the fly being in 1 - 6 ft. I bought this SI unit thinking the SI would aid me in seeing bass on large shallow flats, and seeing bluegills bedded up. The suggestion "2 1/2 to 5 times depth" would mean with the boat in 6 ft of water I should set the range out to no more than from 15 - 30 ft. That's not much. So, I would like some response from people with real on-the-water experience using SI in 1 - 6 ft. Anybody got experience with this?

blue gills on beds...

jworks · « **Reply #8 on:** February 16, 2015, 07:43:56 PM »

Kosmo, that's some really good pics. Thank you very much. I am new to this, so I may ask some dumb questions.
1. I'm assuming the 24.9 Ring is a casting ring ?
2. You were in 2.8 ft of water, and you set the SI range at 99 ft ?
4. On the orange screen is that a 360 degree image? If so I don't think my 899 will do that. What type HB do you have to do that ?
5. On the blue screen I don't know what the 20 and 40 means.
6. What is the 10x on the orange screen?

Humminbird_Greg · « **Reply #9 on:** February 17, 2015, 08:56:41 AM »

Not Kosmo but maybe I can answer your questions:
1. Yes, the 24.8ft. is a casting ring.
2. He was in 2.8 feet of water with the 360 Range set at 99 feet (but was using a 10X zoom) and the Si range was set at 40 feet.
3. You skipped this number… trying to see if we were paying attention weren’t you!
4. Yes, that is one of the possible images from the 360 accessory. Your 899 can do this with the purchase of either the transom or trolling motor mounted 360 Imaging accessory. He is using an ONIX unit but other models can use the 360 Imaging accessory.
5. The 20 and 40 are ranges. He could have opted to show the range lines. Think of the 2D sonar turned sideways. On the 2D sonar you have ranges spaced evenly from the lower range (typically 0 feet) to the lower range. Same with the Si sonar and in both you can choose to show the range lines or not.
6. That is a zoom level for the 360 image.

jworks · « **Reply #10 on:** February 17, 2015, 09:33:59 AM »

Now I understand the 10x. Thanks, Greg. I paid the $85 and did the transducer exchange , just put the HD transducer on the transom 2 weeks ago. Is the 360 option another gadget? If so where is it mounted?

Humminbird_Greg · « **Reply #11 on:** February 17, 2015, 10:11:26 AM »

The 360 Imaging is another gadget as you say and an expensive one at that. We make a transom mounted and a trolling motor mounted version of these: http://www.humminbird.com/Category/Technology/360-Imaging/

jworks · « **Reply #12 on:** February 17, 2015, 10:16:48 AM »

Ok. I just looked it up while waiting for your reply. I like what I read in the manual. Great idea. Have no idea how much it costs. From the looks of the drawings it sticks up high above the transom. Might get this one day. I'll have to settle for SI for right now.

kosmo · « **Reply #13 on:** February 17, 2015, 04:38:02 PM »

Jworks, if you look in some of those holes, you can see blue gills in them. (I run most of them off, playing around, taking snapshots).that picture came from an onix, but your 899 will si just as well (maybe a little better).I thought that this picture would give you a good ideal of what to expect to see in water less than 10ft. (If you increase scroll speed, it will stretch the fish out. (it makes them easier to see)

jworks · « **Reply #14 on:** February 17, 2015, 04:47:17 PM »

Kosmo, yes I can see them. I see what you mean, if you don't look closely you'll miss them.

I scanned through the manual online. That accessory doesn't look like what I thought. I thought it would look similar to any transducer, but it looks like that thing sticks up pretty high above the transom. How high? How much did one cost ?

kosmo · « **Reply #15 on:** February 17, 2015, 05:14:03 PM »

That 360 thingy is kind of expensive. It comes in two versions. One is a transom mount version.The other mounts on the trolling motor.
I didn't mean to distract you with that picture, but I don't have many pictures left that are just showing the si, in water less than 10ft. with blue gills showing.I did find this one.Its from my 998, using the 800kHz. Same thing as your 899, just a little bit bigger screenscreen.Its debatable, but I think I get sharper images with the 998 than the onix.I circled some of the blue gills.

jworks · « **Reply #16 on:** February 17, 2015, 05:46:42 PM »

Yes, I can see them. Thanks a lot Kosmo. Now I'll know what to look for. I see you are set range to 30 ft in that shot.

kosmo · « **Reply #17 on:** February 17, 2015, 07:02:07 PM »

Found another cool shot.this is from my onix, with the transducer mounted on the trolling motor.this is a winter time shot so no fish on the beds.it was still scanning well, but I had to stop.Was afraid I was going to hit bottom

jworks · « **Reply #18 on:** February 18, 2015, 09:20:05 AM »

That must have been old beds from the previous spring. I can still see 5 or 6 fish (I think) about half way down

Alphahawk · « **Reply #19 on:** February 19, 2015, 10:48:40 PM »

I have an 899 on my kayak and won't put it in the water without the unit. I have found bluegill...shell cracker.....beds as far away as 80 feet in as shallow as 2.5 feet of water using 455. Once I learned what to look for I could tell if there were any fish in the beds or not. I bought the unit for this very purpose......and I caught a lot of Gills before but the si unit just makes for epic days on the water. I have hundreds of beds marked on 5 bodies of water and it is nice to be able to tell if fish are there or not before making the first cast.

Regards

jworks · « **Reply #20 on:** February 20, 2015, 10:22:13 AM »

Alphahawk, I'm looking forward to getting into this if the weather will just start warming up some. (So much for Al Gore's global warming!). Usually here in Alabama this time of year you get a week or so of cooperative weather in Feb when a few large bass start to move in. I was hoping to get to try the SI out for that. Not this year. Then later on bluegills in April-May.

From what I've read it seems you have to kind of play around with settings like sensitivity everytime you go out depending on water conditions. I know I'll catch on to it but it may take awhile. I've not used the 899 enough to know what sensitivity to use in examples like you said.....80 ft out. I think the default is around 10

Whatever, I would assume you'd have to use perhaps a higher sensitivity the further out you go ? I've also noticed the Enhance feature. And Sharpness and Contrast. Not sure just yet what that's all about.

Bob B · « **Reply #21 on:** February 20, 2015, 10:36:11 AM »

Actually, I think the default SI range is more like 150'.......You have to narrow it down to where you would normally use it.

jworks · « **Reply #22 on:** February 20, 2015, 10:52:43 AM »

Bob, yes. The default range is something like that....120 or 150 ft. I was referring to Sensitivity. I think default Sensitivity is something like mid-way on the scale and set at 10 , I think. But you can change that way down and way up to something like....20. The numbers I'm using may not be exact, but the imp thing is I think default is set right in the middle of the scale. I was wondering if Sensativity should be turned up higher than the default setting if range is greater than the default range and Sensitivity turned down for shorter than default range. In Alphahawk's comments he was using 80 ft range. That's shorter than default.

In other replies above you can see on the screen shots they were using range of 75 ft and 30 ft. and 20 ft. For those, I have no idea what Sensitivity was used.

Bob B · « **Reply #23 on:** February 20, 2015, 10:57:20 AM »

Sorry, I misunderstood ..... You are correct that the default is 10 and the range is 0-20.

The range will affect your sensitivity adjustment to some some extent, but the primary thing is the bottom hardness.

jworks · « **Reply #24 on:** February 20, 2015, 11:09:05 AM »

In those screen shots above, the bottom appears not the darkest or the lightest shades where the beds are. I assume that means a somewhat firm bottom but not rock or hard clay and not really soft deep mud.

I can see where you could really get carried away with technicality in this stuff, when actually all that matters is whether you see the beds or not.

jworks · « **Reply #25 on:** February 20, 2015, 11:11:39 AM »

I like to fish Lake Guntersville started late Feb to early March. The nice size bass will begin moving into shallows then. The heavy grass which the lake is noted for is not yet been reborn so I would think you should be able to see nice size bass on the SI in the large shallow flats (1 - 8 ft ).

Bob B · « **Reply #26 on:** February 20, 2015, 11:32:33 AM »

The other thing that makes a difference sometimes is the color pallet. The blue is better for me in lower light conditions, but in bright sun I like the amber, and sometimes the green pulls out the details better.

jworks · « **Reply #27 on:** February 20, 2015, 11:50:41 AM »

Bob, I'll try to remember that. Blue for low light, amber for sun. Should be easy to remember, Amber is like the sun.

If I remember right I think the Amber 1 is the default pallet. It has an Amber 2 on it too. I read somewhere somebody said the newer Amber was better as the Amber one he'd been using was kind of washed out or something like that. I looked at both, couldn't see much difference. I'll try the green too.

Bob B · « **Reply #28 on:** February 20, 2015, 11:54:04 AM »

The color pallet preferences vary a lot between people......best thing is to pause the screen when you see some interesting stuff and switch the color pallet around to see what looks best.

jworks · « **Reply #29 on:** February 20, 2015, 11:56:41 AM »

That's a good idea. I like that. To pause, just hit one of the cursor arrows, right? (right, left, up or down)

Bob B · « **Reply #30 on:** February 20, 2015, 11:59:08 AM »

jworks · « **Reply #31 on:** February 20, 2015, 12:20:44 PM »

Couple of other questions:
1. Have you ever used the Keel Offset feature? If the transom sits 1 ft deep do you set Keel Offset -1 or +1 ?
2. Have you played around with the Enhance feature and Sharpness ?

Humminbird_Greg · « **Reply #32 on:** February 20, 2015, 02:10:46 PM »

1. This would depend on whether you want to know the depth of the water between the keel of your boat and the bottom of the lake/river or if you wanted to know the actual depth of the water (from the surface). If your transducer was mounted on the bottom edge of your transom and the transom was the lowest point on the boat; you would leave the Keel Offset (also called Depth Offset) at 0.0. If the transducer was mounted on the transom but it was not at the bottom edge or you had an actual keel that stuck down further into the water (like on a sailboat); you would use a negative (-) setting to show the amount of water between the bottom of the boat’s keel (lowest point of the boat) and the bottom of the river. If you wanted to know the depth of the water from the surface you would use a positive (+) setting.

2. When you change the SI Color menu setting, you will want to use the SI Enhance menus (Sensitivity, Contrast and Sharpness) to further adjust the image so that you can see fish and/or bottom structure.

Bob B · « **Reply #33 on:** February 20, 2015, 02:20:41 PM »

Yeah ..... I forgot to mention the SI enhance....Turning it on will make the fish show up better.
I usually just use the low setting. You can get even better fish contrast on the higher setting but things get pretty grainy.

jworks · « **Reply #34 on:** February 20, 2015, 03:38:09 PM »

Greg, my boat is a center console type boat (17.5 ft Key West). I'm thinking I should use the (-) . Picture attached. I think the 899 allows for only 1 ft increments (no inches) in the Keel Offset. Dead in the water the low point of the transom is about 1 ft deep. Transducer is I'd guess about 6 - 8 inches up from that. My main concern is not getting a boat this heavy stuck on a mud flat when I go to the marshes in so. La. Big time trouble ! Although, I've seen a few places here on Lake Guntersville that shallow too, when they open the gates. In water that shallow its sort of like splitting hairs I guess. I use to run those flats in south La fast when I had a bass boat and lived down there. With a 25" shaft on this motor, I don't feel comfortable doing that now though.

Humminbird_Greg · « **Reply #35 on:** February 20, 2015, 04:03:49 PM »

Are you sure that isn’t the Depth Offset menu and it has 0.1ft. (1.2”) adjustments to it jworks?

I’ve heard about boats getting stuck until high tide down there. We were almost stuck a few times too. The guide was blasting mud and oysters out the back end of the boat and made us “fat guys” get up front! I just could not imagine how bad it would be to spend a night out in the open on one of those South La. marshes. I bet you would look like a dried prune in the morning by the time the mosquitoes were done with you.

jworks · « **Reply #36 on:** February 20, 2015, 04:18:54 PM »

I'm not 100% sure. I'll have to look. Its just too darn cold to go out there right now. But I will check. I have an Eagle 350 on the boat too. That one calls it Keel Offset, I know that for sure. But I'll check on the HB.

You're right about the mud. It is definitely NOT a place to play around and zip around without being a regular fisherman there. I got stuck once in a bass boat. I missed a turn at a "Y" and when I realized I was in a dead end canal I looked at the depth finder. It was not reading; then looked behind me and solid mud was kicking up. I did my best to make a U turn and squatted right there - which I knew was going to happen anyway. I had no push pole. Sun was lowering and I had no choice but to get out of the boat. Sunk up to my crotch in muck. Lifted the rear of the boat enough to push it forward maybe 8 inches as my step son had the troll motor on high just under the surface. Then pull myself up and back down in the muck again and repeat. Did this over and over till finally the boat would rock just a little. I was much younger then, and had enough strength I guess to break the suction. We got out before dark but man was it close. Never again! No fish is worth spending the night out there like that with mosquitoes eating you alive. After that trip I bought a push pole. Even so, pushing a center console off a mud flat in 6" of water would be a daunting task, especially at my age now.

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