Which one SI or DI ?

[Perch jerking]

I mainly spider rig. Wanting a new unit when I upgrade TM. Wanting to add it to TM. ? Does the SI units also so DI or just 2d sonar. If they make one that shows both which one does. Thinking I would just be happy with DI up front. Thanks

[CrappiePappy]

I'll let the others elaborate on most of your questions, but here's my on what I've read :

Humminbird has the best SI, but their DI is an interpretation of the SI image.
Lowrance has the best DI, as they have a dedicated crystal strictly for DI imaging.

Most all the upper grade units will do SI/DI/2d.

Personally speaking ... I have a Lowrance Elite 5DSI mounted on TM, and I don't miss the 2d (the E5DSI is down scan only). My unit has been discontinued by Lowrance, and 2d added ... now called the Elite 5HDI.

According to a lot of members here, "Brian@BBGmarine" can give you the best deal on whichever unit you decide on ... and can even suggest the best unit for whatever purpose you intend to use it for, or where you mount it.

... cp

[Redge]

Pappy has given you some great advice!!

[Buckie02]

Get the biggest screen you can afford. I have a 898 and love it. Will get an 1199 as soon as wife aproves it.

[rnvinc]

*2d shows a "cartoon like" image of stuff under the boat...
*DI shows a "picture like" image of stuff under the boat...and out to the sides a few feet...
*SI shows a "picture like" image of stuff under the boat, out to the sides 100+ ft...and which side of the boat...


SI advantage is finding structure....(even far out to the sides of the boat)...

Then re-position the boat to effectly fish that "new-found structure" with the DI or the 2d...


Rickie

[TNAMBUSHER]

I mainly spider rig. Wanting a new unit when I upgrade TM. Wanting to add it to TM. ? Does the SI units also so DI or just 2d sonar. If they make one that shows both which one does. Thinking I would just be happy with DI up front. Thanks

I am no "spider rigger" BUT if you mount ANY type unit on the TM, your baits are already well past any structure that shows up WHEN it shows up. If that is going to be your primary technique, I do not see the benefit of a TM mounted sonar. Am I missing something? The only way that I could see that a front mounted sonar would be useful for SR'ing would be to mount an SI transducer on some sort of articulating mount, set it to scan from one side and then "sweep" the beam from side to side so that it showed cover in the boats path.

[clfarms1]

What it does do is let you see the depth of the fish, if there are any drop offs that the fish are setting on.but mainly if there are any fish there to catch

[brush pile]

I have always had a depth finder up front and I do spider rig. If I am fishing 14 ft rods then most times I am spot on with what I am seeing.

[crappielimits]

I am no "spider rigger" BUT if you mount ANY type unit on the TM, your baits are already well past any structure that shows up WHEN it shows up. If that is going to be your primary technique, I do not see the benefit of a TM mounted sonar. Am I missing something? The only way that I could see that a front mounted sonar would be useful for SR'ing would be to mount an SI transducer on some sort of articulating mount, set it to scan from one side and then "sweep" the beam from side to side so that it showed cover in the boats path.

I don't think you are truly understanding Spider Rigging! You are not moving when over the fish. I basically see fish/structure and let wind/current drift me back over them. You want your lines at a 90 degree angle to the rod. This keeps them as close to straight down allowing for depth control. Maybe you are thinking of pushing or long lining?

[crappielimits]

What it does do is let you see the depth of the fish, if there are any drop offs that the fish are setting on.but mainly if there are any fish there to catch

This is exactly right! You are trying to put a buffet right in the fishes face. It's a must to see depth, especially for suspended fish. You must key in on the prime depth. Same with fish on structure or drop offs. This can be done with a transom mount transducer or through hull, but it is ideal with the trolling mount and console unit turned around to see depth changes. Allowing you to better zero in on depth changes or structure.