Need help understanding SI...

[East TN Basser]

I just ordered a new boat and put two 798's on it so I'm trying to do some homework while my boat is being built. I've been looking at the images on here and they are awesome, one question: If I'm scanning with SI and I've got it set for 40 feet out on each side, or any distance on each side for that matter, if something shows up on my screen, say on the right hand side, how do I know where exactly within that 40 foot range the object is? I've seen some set to scan like 120' on each side, how the heck do you know where exactly in that 120 foot scan your object is? Thanks

[Bryanmc57]

The latest SI software update added si "range lines" so you can get a pretty good idea how far off to the side it is. Also, you can move the cursor over to the object and it will tell you how far away it is.

[East TN Basser]

that makes since, thanks dude..

[T Mike]

Use your cursor and swing it over to the object "you wanna know where it is" and then hit MARk and it will mark a waypoint at that spot. Spin the boat around and bring up your GPS screen and go to the waypoint. Thats the beauty of SI :)

Mike

[East TN Basser]

Thanks. I can't wait to get out there...

[microsalmo]

great information. i too just ordered a boat. is there a SI beginners thread or trainind DVD out there somewhere?

[DIXIEDOG]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by microsalmo &raquo;</td></tr><tr><td class="quote">great information. i too just ordered a boat. is there a SI beginners thread or trainind DVD out there somewhere?</td></tr></table>

Best one I've seen is this video by Doug...he's got several videos but I'd start here then check out the others on his channel

[Doug Vahrenberg]

This thread will teach you about the range line feature: http://www.bbcboards.net/zerothread?id=682053

One thing you can do is change the area of coverage and you will change the range lines and can find exact distance from the transducer without stopping the screen...

[Reelsore]

I read and continue to read this forum and when I got mine installed, it made the learning curve easier.The amount of settings that Doug tells you are a very good starting point. I wrote down a cheat sheet of his settings, applied them, and it made it easier from the start. Thanks Doug.

[gomer snerd]

Easy. Say you are set at 100 ft per side. A stump appears about halfway between the center to the edge of the screen. 50 ft over. If it is a third way over from center- 33 ft. Three fourths-75 ft. Simple.

[DIXIEDOG]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by gomer snerd &raquo;</td></tr><tr><td class="quote">Easy. Say you are set at 100 ft per side. A stump appears about halfway between the center to the edge of the screen. 50 ft over. If it is a third way over from center- 33 ft. Three fourths-75 ft. Simple.</td></tr></table>

Does this take the water column into account?

[gomer snerd]

starts in center and disregards the column if scanning both sides

[Doug Vahrenberg]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by DIXIEDOG &raquo;</td></tr><tr><td class="quote">

Does this take the water column into account? </td></tr></table>

Water column is still distance. If a fish was 10' down or 10' over it would still be displayed at 10' to the side of the centerline.

[DIXIEDOG]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Doug Vahrenberg &raquo;</td></tr><tr><td class="quote">

Water column is still distance. If a fish was 10' down or 10' over it would still be displayed at 10' to the side of the centerline.


</td></tr></table>

So the water column is basically a 45 deg cone of coverage? Same depth as width per side?

[Doug Vahrenberg]

Water column displays both side readings, down and everything in-between. It's distance from the transducer.

[DIXIEDOG]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Doug Vahrenberg &raquo;</td></tr><tr><td class="quote">Water column displays both side readings, down and everything in-between. It's distance from the transducer.

</td></tr></table>

So how is this affected when you use the contour option?

[Doug Vahrenberg]

Displays only the bottom data since the unit knows depth from the 2D sonar readings and they unit can them eliminate the water column.

[DIXIEDOG]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Doug Vahrenberg &raquo;</td></tr><tr><td class="quote">Displays only the bottom data since the unit knows depth from the 2D sonar readings and they unit can them eliminate the water column.

</td></tr></table>

What I'm not understanding is when you switch to contour mode the only thing that changes is the water column is gone....the two "solid" portions of the screen are pulled together to make one surface....that originally led me to believe that the water column should be eliminated from all side ranging distance calculations.


Using two of your pics from another thread




If you measure from the centerline of the screen to where the ramp ends on the normal SI view it is 1.375 from the center, now measuring the Contour mode it is just over 1"....that leaves 3/8" missing....that 3/8" is the width of the water column at that point....that's what makes it confusing to me.

[Doug Vahrenberg]

THe Countour mode changes things as it marries the two sides but represents directly below the boat what the bottom looks like.

[ClaySlayer]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by East TN Basser &raquo;</td></tr><tr><td class="quote">I just ordered a new boat and put two 798's on it so I'm trying to do some homework while my boat is being built. I've been looking at the images on here and they are awesome, one question: If I'm scanning with SI and I've got it set for 40 feet out on each side, or any distance on each side for that matter, if something shows up on my screen, say on the right hand side, how do I know where exactly within that 40 foot range the object is? I've seen some set to scan like 120' on each side, how the heck do you know where exactly in that 120 foot scan your object is? Thanks </td></tr></table>


Is the 798 at the console going to be flush mounted or on a ram mount? Either way, if there's room I'd upgrade to an 898 or 998. This coming from the owner of a 798 with a buddy that has an 898. The images will be crisper on the 898 or 998 and you can bump the range out to ~100' or more without penalty whereas on the 798 you have to stay at ~50ft or less to have a sharp image.