Si ?

[brettw]

if I want to only scan the water and not the bottom?

[rnvinc]

if I want to only scan the water and not the bottom?

Set SI Range to the water depth...

Rickie

[rnvinc]

if I want to only scan the water and not the bottom?

Set SI Range to the digital readout water depth...

(It may be called something else in Lowrance)...

Rickie

[brettw]

thinking of suspended crappie in the winter

[rnvinc]

thinking of suspended crappie in the winter

Also set the image frequency to 455kHz...(I think I read the total coverage of the Lowrance 455kHz is about 130° side to side)...

The image may have a little less detail than the 800kHz beam but the wider beam shape of the 455kHz will reach more of the suspended fish out to the sides towards the surface...

Just remember that setting the SI Range to the water depth also limits how far out to the sides the display will show echoes...

For example...: in 20' of water depth....Setting SI Range to 20' left and right will only display echo returns from 20' left and right....

In this same 20' of water depth....if there are suspended fish 30' out to the sides of the boat...the SI Range must be set to farther out than 30' for the display to show those fish...in which some of the bottom would have to show on the display...

What this means is...there is no way to show suspended fish (on the display) that are physically farther out to the sides than a "SI Range" setting of a value equal to (or less than) the water depth...and not show some of the bottom on the display (in any brand)...

Rickie

[rnvinc]

Also set the image frequency to 455kHz...(I think I read the total coverage of the Lowrance 455kHz is about 130° side to side)...

The image may have a little less detail than the 800kHz beam but the wider beam shape of the 455kHz will reach more of the suspended fish out to the sides towards the surface...

Just remember that setting the SI Range to the water depth also limits how far out to the sides the display will show echoes...

For example...: in 20' of water depth....Setting SI Range to 20' left and right will only display echo returns from 20' left and right....

In this same 20' of water depth....if there are suspended fish 30' out to the sides of the boat...the SI Range must be set to farther out than 30' for the display to show those fish...in which some of the bottom would have to show on the display...

What this means is...there is no way to show suspended fish (on the display) that are physically farther out to the sides than a "SI Range" setting of a value equal to (or less than) the water depth...and not show some of the bottom on the display (in any brand)...

Rickie

I don't like my own wording in blue above...

I should have said...

There is no way to display suspended fish without the bottom showing ...when the fish reside at a distance farther away from the xducer than "a value of equal to or less than the digital water depth"...

(I don't like that wording either but I think it is more correct)...

Rickie

[gotta_fish]

Your way over my head here .Does side imaging need the bottom to show us the shadows of suspended fish?

[genec]

Yes, SI must have pic of bottom in order to show shadow, like a light shinning on a pole the shadow is behind it but you only see it is when shadow touches a object or bottom or something the shadow can leave us a pic

[brettw]

so, you can't limit the depth, and then go much wider on the side image,
,30 ft of water, depth set at 25, si set at 80, for example

[rnvinc]

so, you can't limit the depth, and then go much wider on the side image,
,30 ft of water, depth set at 25, si set at 80, for example

Correct...

If the water depth is 30 (in your example)...there is no way to set the SI Range out farther than 30' without some of the bottom showing in the SI image...

Rickie