I am fishing out of a 1648 aluminum Jon boat with a 55 pound thrust Minn Kota, and a 40 hp tiller outboard. I fish mostly electric only lakes because they are close There is one large lake two hours away. I have a Helix 5 Chirp 2d mounted on the bow with the transducer mounted on the transom. The Helix sits on two 4" arms in an effort to get it closer to where I can see it. I am not very good with electronics and doubt I am getting all the Helix 5 has to offer.

I want to do some upgrading because; 1. The Helix 5 is still hard to see. 2. I would like to have the transducer underneath where I spend the most time. 3. When on the big lake I would like to have a unit to tell me where I am and if any bait fish are present while I use the outboard. 4. I thought I would give SI a try.

There is a Hummingbird rebate going on and I thought I would spring for a Helix 9 SI Mega G4 (and whatever letters is in the model name). The Hummingbird site says I must have a 80 pound thrust to mount the transducer on the trolling motor. i thought this strange but decided it had to do with the diameter of the motor head to match the transducer mount. Am I correct?

If so that takes me down to the Helix 7 SI Mega G4. and mount it to my existing trolling motor. I would move the Helix 5 to the where I sit while using the tiller. From searching the forum Mega seems the way to go for better clarity and also up grade to a HD transducer.

Does this make sense? Pros and cons I should be aware of?

I hope to use the Helix 5 power cord to run the Helix 7 to avoid rerouting so many cables. I'll have to talk to Hummingbird.

Your thoughts, tanks.