Helix MDI or Helix MSI?

[yankee]

Ok guys I am having trouble making a decision on a Humminbird fish finder/gps unit.  I have purchased a couple years ago the Ulterra trolling motor with the MDI transducer incorporated in the shaft.  I have no intentions of ever replacing this trolling motor unit.  So now I am wanting the Humminbird unit that matches up to this motor unit and that would be the Helix MDI at the minimum.  From what I understand the Helix MSI will work, it just will not project any side image due to the MDI transducer being used. The exrta cost is close to $300 for the side image but not sure it would ever get used in SI mode?  So any thoughts you guys may have would be appreciated.

Everyone have a Merry Christmas and be safe.

[Juan]

I wish they'd put a transducer in the saltwater Ulterras. There's just no good way to connect an external unit. I've given up trying.
IMO the Humminbird you pick should depend on how and where you fish. I have a Lowrance on the Sea Pro with both DI and SI and for the bay and open water, I almost always use only the DI. SI is almost useless in the open water. That said, I recently bought a 7" Humminbird Helix with both DI and SI (because it was on sale) for my river boat. In the river the SI really shows a lot of structure that the DI would miss and it covers a larger area.. SO, if it were my decision, I'd get the one with SI if I fished mainly fresh and shallow waters. For anything else, the DI is more than enough imo.

MERRY CHRISTMAS

[yankee]

After more searching I found that (according to Minn Kotta) the SI model Helix will not work "as efficiently" on the Ulterra DI transducer. The DI will only work in the Wide Range setting and not the Narrow Range. Soooo, I went with the Helix Mega DI+ unit. Back ordered until January, not too long of a wait.