16' Sea Ark stick steer so not a lot of room,,,I want one head but read both transom trans and trolling motor trans, and just rotate the head.

I don't need to read both at once just while sitting up front. Looking hard at Helix si gps either 5 or 7. I just don't want to have 2 head units for this small boat plus I'm not rich..lol Using hand controlled Trolling motor no remote.

I believe Helix 5 si gps  with extra xtm 9 hwt would work with Y cable but can someone verify and do I need the $90 HB switch?? Thanks in advance.

Helix 5 or 7 

Looks like you need the switch. If you use the Y cable, i believe you will get some type of return from both transducers at the same time

I asked HB but no answer yet,,,wondering if the switch comes with all the wires needed minus "y" cable.Thx

HB site not very helpful sometimes,,,,they show switch but don't show cables which I have diagram of,,,,

https://humminbird.johnsonoutdoors.com/sites/johnsonoutdoors-store/files/assets/misc/HU/H/HUM_productmanual_IG_TS3_531870/HUM_productmanual_IG_TS3_531870.pdf

You need a switch. If you are using 2 identical transducers.

 

My boat has 2 transducers without a switch, but they are doing different things.

 One is a shoot thru hull for 2d and depth.

The other is on the transom for side and down imaging. This is pretty common on fiberglass boats.

If I unhook the shoot thru there is no depth reading. If I unhook the transom there is no imaging.

It takes a special cable but it works. The reason for the shoot thru hull is to still get depth readings while on plane.

 

On a 16 foot boat I would just use the transom transducer all of the time? Why mess with 2 transducers?

Ok,,,,so if I get a si unit it will read side close to shore line as I troll good enough? I thought I needed one up front mounted to trolling motor as well,,,,,,,I see ur point,,,16' is not that big and if I speed up or adjust my return speed to match my trolling speed it should view pretty well,,,,Am I thinking correctly? Thx

The Helix 7 or 5 with all the bells and whistles should be fine....the 5 is around $500 the 7 is around $700. and they both have ability to do one side at a time I understand,,