I bought a humminbird 798 si di combo. I was wondering if anyone could give me a few tips to get me started.
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I bought a humminbird 798 si di combo. I was wondering if anyone could give me a few tips to get me started.
I am assumeing the 798 is like the 898, so keep your screen speed slow around the same speed you are running in the boat. The slower you go the better the pictures will be. Google some of the humminbird forums, there is a great deal of help on those. I think you will like the 798 and good luck to you.
Try these settings...:
SI sonar beam...800kHz in water deeper than 5ft....455kHz in shallower...
SI Range...60-70ft (left and right)...in water less than 20ft...
Chart speed ..match boat speed
Pallette...color that looks the best to you...
Go in SI Express menu (1"Menu" click)...cursor down to "SI Enhance"...cursor right to open...
I keep the "SI Enhance" window up on my screen anytime I am viewing SI...
Set "Contrast" ....10-12
Set "Sharpness" to "Off"
Set "SI Sensitivity" setting as a "brightness" control for the SI image (as different water conditions/bottom compositions will make the image brighter/darker..)
SI Sensitivity up will brighten the image...
SI Sensitivity down will darken the image...
I frequently change this SI Sensitivity setting as my SI image changes in brightness...
Rickie
Rickie, do 798 have 800 khz ? also if water is 30 feet ,should I be wider screen, I mainly am using only one side to help give me a better detail until I can learn it better. I also am having a problem with unit as I get about 15 feet and go deeper it starts to cloud out much of the time even cutting motor and everthing else off,changing sen and contras do not help and if near hard bank even worst,when I find out how to take pictures with it ,will post them
We have to remember that the water depth is figured in to the SI Range setting...
If the unit is set to 60ft SI Range (and the water depth is 30ft)...only 30ft of bottom will be visable left and right...
Viewing one side only (like you mention) is definitely a good way to make structure look larger on the 798 screen...
Also.....A pic of the cloudiness would help when you get a chance...
Rickie
To take screenshots..
Insert a SD Card...
Go to the last tab on the right in the main menu...
Cursor down to "Screenshot"
Turn it "On"
Now pushing the "Mark" button on the front of the unit will take a screenshot of what is showing on the screen..( and mark a waypoint of where the boat was when the "Mark" button was pushed)..
Rickie
Rickie,thanks for the report, but what happen to first 30 feet of bottom ,is it shown on DI ? would a log at 25 feet on BOTTOM show up ? I always heard ,people may think you are dump but if you speak ,they will know it, look like I just prove it ,LOL
The SI Range setting is not the "bottom coverage left and right"...
The water depth is figured in to the SI Range setting...
If the SI Range setting is set at 60ft .... The actual bottom coverage is 60ft minus (-) the water depth...
So if the water is 10ft deep... The bottom coverage is 50ft (left and right)
If the water is 20ft deep... The bottom coverage is 40ft (left and right)
Etc..
In theory.. The SI Range setting would best be defined as "feet away from the xducer" instead of "feet of bottom coverage"....
The unit does not start counting at "zero" (0) from where the SI beam first contacts the bottom...
The unit starts counting at the xducer as "zero" (0) ft away from the xducer ... Then counts the feet down to the bottom...then continues on ...counting feet out to the sides until we reach the SI Range setting....
If we watch SI screen as the water depth changes...the outside edges of the screen (the SI Range setting) does not change as the water depth changes... Only the water column changes (by getting wider or narrower)...This is because the water column "depth" is the first part of counting the "feet away from the xducer" (in the SI Range setting) ...and the remainder of "feet away from the xducer" is bottom coverage...
Rickie
Good explanation Rickie! Thumbs Up
But you get 60' of the upper 10 feet. Right?
To get 60ft of linear bottom to show on the screen.. Set the SI Range setting to an equation of "60 + water depth"...
If the water depth is 10ft... The SI Range setting should need be set at 70ft to show 60ft of linear distance bottom...
Because the first 10ft of the linear "70ft SI Range" setting is the 10ft of water column...
An extreme example (but still true) would be...
If the SI Range setting is 60ft (left and right)...and..
If the water is 50ft deep...
Only 10ft of linear bottom would be showing (left and right)....
Because the first 50 linear feet of the 60ft SI Range setting is 50ft of water column...
Rickie
Thanks guys,that was great information
This is all very helpful for first time si guys. keep it coming.
If I understand this right, If straight under boat bottom is 20 feet and SI is on 50 ,then 30 feet of SI is really all I see because the rest would be off screen? hope I am not making you upset,just slow at learning anything thats computerize. THANKS. As I see it now ,its like in a house and measuring the wall to the floor, then measure the floor andif room is 20 feet and wall is 10 feet , I would need SI set 30 feet to reach other wall?
I think you are getting it...
The SI Range setting has been misconstrued by HB customers from the very beginning of SI's introduction into the marketplace...
The confusion is understandable because the HB advertisement says ..."480ft of bottom coverage can be seen with the HB SI"....so people just automatically think that the HB "SI Range" setting is what gives this advertisement of 480ft...
In reality... The "SI Range" setting is an equation of 2 separate linear distances added together...
The first linear distance is the water column...(depth of water in ft)..
The second linear distance starts at the point where the SI beam first contacts the bottom (straight down) and reaches out along the bottom until the remainder of the SI Range setting is reached...
An easier way to see this SI Range setting equation is turn on the "Range Lines" in the main menu...(I think its under the sonar tab in the latest software update)...
As soon as the "Range Lines" are turned on (in the SI View)... The actual water depth your boat is currently in will be displayed on the SI image at the exact point where the "dark blue water column" touches the "lighter blue bottom"...
This is because SI Range setting first measures straight down ... and then continues measuring out to the sides until the SI Range setting is reached...
Rickie
Rickie, I really thank you, i would have never figured that out,I am glad this board have people like you with knowledge that is willing to help us that are struggling and it has been many on this board and so I want to thank all of you
Ricky, I also thank you for this explanation. Gene & I were fishing Thursday and trying to learn as much as we can about DI/SI.
Thanks again.
thanks good information
imonbass's Channel - YouTube according for this guy 60' gives 60' bottom and 60' surface. you don't have to do math..is he teaching wrong for hb??
Im going with Rickie on this one. But we both could be wrong.
The Si Range is actually the slant range from the transducer. Think back to your geometry days (or daze for some of us! :confused: )… remember this:
Attachment 82978
Well the Si Range is that side “c”.
Point “B” would be the transducer mounted to the boat.
Side “a” would be the water column (water depth).
Side “b” would be the lake bottom that is shown.
I watched the video that was posted and did not hear Doug contradict this. If I missed something in it, please post back the time stamp for that section.
Now that Greg has cleared that up for us...I must go back and clarify a statement I made in my own quote above (highlighted in blue)...
My statement (about the SI Range lines) is incorrect....
The SI range lines are inserted onto the SI image in a division of 4 ...of the SI Range setting...
"SI Range setting divided by 4"..= Range lines on the SI image
If the SI Range setting is:
40 ft..the range lines will be 10, 20, 30, 40
60 ft..the range lines will be 15, 30, 45, 60
70 ft..the range lines will be 17, 35, 52, 70
80 ft..the range lines will be 20, 40, 60, 80...etc...
I hope I didn't confuse anyone...
Sometimes I have to actually go work with my unit...instead of trying to remember all this techno stuff...
Rickie
So Rickie if the unit is set on 50ft. that is 50ft. from the transducer?
Referring to Greg's post with the geometry triangle...
The SI Range setting is the linear distance (in a straight imaginary line) from the xducer (sloping down and out to the side) to a point on the bottom that is equal to the SI Range setting...
This "slant range" as Greg calls it is basically the Pythagorean Theorum of a "right triangle"...
"a" (squared) + "b" (squared) = "c" (squared)
In this "slant range" formula that HB is using... The deeper the water... The less % of the SI Range setting will be actual bottom coverage....
What does this SI Range setting mean for us HB users...??
1. Set the SI Range setting at a small enough setting so that structure on the SI image is descernable....(the higher the SI Range setting - the smaller structure will appear on the image)....
2. Objects on the SI image are closer to the boat than they appear on the image (because the water column depth is figured in to the SI Range setting's "slant range" formula)...
3. The SI Range setting is "not" the actual bottom coverage...
Rickie