Over the last month, I've seen a few good deals on used SI units and I keep telling myself to go ahead and pull the trigger (PS: don't tell my wife).

Does anyone on here currently use an SI unit on a jonboat?  I have a 15ft G3 with a 65 lb bow mount and a 80 lb transom mount and I get ~4.3 MPH when I "floor it".  Would that be fast enough to get a good picture out of the SI units?

I'm also debating what I'd actually set up on my boat.  For instance, I fish the small, electric-only lakes only so there are no Navionics chips available for me (that I know of) -- and I'm even debating the need to set up the GPS with an SI unit since my lakes aren't on fishing maps.  So I'm even almost thinking I'd just need the head unit and the transducers.

Thougths?  Input?  Bueller?  Bueller?

Yes 4mph is plenty fast enough. I got good readings at 1/2 mph on the slowest chart speed and glassy waters in a jon boat. I also get good readings at 5mph with a slight chop. Calmer waters produce clearer pictures due to the boat not rocking. More stable the boat the clearer the picture

I don't have a Nav Chip either, but since its only a few more dollars (comparatively) for the GPS antenna I would get it. Mine came with it.  Bought it used for $1K from a salt water forum. he was upgrading to the biggest screen and selling his big screen.

Chris,  4mph is plenty fast.  The GPS system is built into the unit.  All you would need is the GPS cord with the dome at the end and your good to go.  Might as well get the GPS to make sure your actually going 4mph  .  The only downside of a SI on a non gas motored boat is when you turn the trolling motor head it will smear/distort your picture.  

Mike

Chris,  4mph is plenty fast.  The GPS system is built into the unit.  All you would need is the GPS cord with the dome at the end and your good to go.  Might as well get the GPS to make sure your actually going 4mph  .  The only downside of a SI on a non gas motored boat is when you turn the trolling motor head it will smear/distort your picture.  

Mike

By the way, I blame you for putting the SI bug in my head.  That screen on your boat is bigger than the freakin' TV in my bedroom

Chris, 4mph is plenty fast. The GPS system is built into the unit. All you would need is the GPS cord with the dome at the end and your good to go. Might as well get the GPS to make sure your actually going 4mph . The only downside of a SI on a non gas motored boat is when you turn the trolling motor head it will smear/distort your picture.

Mike

By the way, I blame you for putting the SI bug in my head. That screen on your boat is bigger than the freakin' TV in my bedroom

LOL.  Thats right you were the first one to see my 1197SI right??  It's nice....  You'd be decked out with one of those on the jon   8-)  LOL

Mike

Chris,  4mph is plenty fast.  The GPS system is built into the unit.  All you would need is the GPS cord with the dome at the end and your good to go.  Might as well get the GPS to make sure your actually going 4mph  .  The only downside of a SI on a non gas motored boat is when you turn the trolling motor head it will smear/distort your picture.  

Mike

By the way, I blame you for putting the SI bug in my head.  That screen on your boat is bigger than the freakin' TV in my bedroom

LOL.  Thats right you were the first one to see my 1197SI right??  It's nice....  You'd be decked out with one of those on the jon   8-)  LOL

Mike

It's just a bit of a tough pill to swallow to drop $3k on electronics for a $2500 boat.  But I think I'd get over it real fast (if the wife let me).  

Sound like putting a flat screen TV in an outhouse. ;D

Hey T-Mike, or others who would know...

What's the minimum speed you can go and still get a decent picture on the SI unit?  Keep in mind, I'm electric-lake only, so my speed options are 4mph and less.  Just curious if I could get a decent picture using only my 65lb bow mounted trolling motor

The lowest speed I have gotten good results with is .7 mph.  I would definately hook up the gps antenna.  With it you will be able to accurately mark exactly where all of the stuff you find with side imaging is located.