Losing depth reading on plane

Revtro · July 19, 2018, 02:34:08 PM

I have a Garmin and a Humminbird unit, both with pucks mounted on the transom. One of them is in the spot the previous owner used and the other one I mounted on the other side of the motor. Both units are losing their depth reading when I get up on plane. Ok, so what's the conventional wisdom on where to mount the pucks? I do not have jackplate, so my motor is fixed.

Thoughts?

dartag · July 19, 2018, 04:55:28 PM

Only way to get good bottom when running is having a Thru Hull Transducer. When your on plane the transducer will be out of the water. I ended up buying a 5 inch HB Helix and epoxying the transducer to the hull in the back. Works great.

Revtro · July 19, 2018, 05:03:22 PM

Can a sidefinder transducer be epoxy'd in or do I have to purchase a special thru hull transducer? What about lowering the transducer more toward the motor so it's in the water when on plane? Would the prop wash be an issue?

dartag · July 19, 2018, 06:26:59 PM

You can try to put the transducer in. Duct tape or put a sand bag on it to hold it down and see if it works. Not sure if the side scan will work shooting through. Problem with putting it below the transom is if you hit bottom it will get ripped off.

My HB transducer is the one you would mount on the back that I glued to the inside of the hull

Hollada · July 19, 2018, 11:05:34 PM

Your SI ducer stays where you have it. The shoot thru goes in your bilge and connects via a Humminbird y cable. The y cable replaces the sonar signal from your SI ducer with the shoot thru.

Let me know if you have questions.

Revtro · July 30, 2018, 02:28:24 PM

How do you switch between transducers? Is it automatic or do you have a switch?

motocross269 · August 08, 2018, 09:06:53 AM

It's automatic... The thru hull only reads the 2D sonar and the Transom ducer is for the SI....It's been awhile but you may have to set it up in "Settings" but once you do that you are done...My boat is currently up North or I would take some pictures or have you over to copy my setup..It's pretty straight forward though...

Hollada · August 08, 2018, 05:04:55 PM

Nothing to change in settings. The y cable replaces the sonar from the si ducer with the sonar from the shoot thru.

Your unit only sees a si ducer. It doesn't know the sonar is coming from a different ducer.

motocross269 · August 14, 2018, 01:32:33 PM

That's what I thought but couldn't remember if I had to so something in settings for sure......It's been about 6 years ......

Funny thing is my 2D transducer quit reading bottom this weekend so I will be standing on my head in the bilge this week installing a new transducer and cable...

Hollada · August 14, 2018, 03:12:33 PM

Test twice... epoxy once :-)

djkimmel · August 14, 2018, 05:06:14 PM

You lose sensitivity when you shoot through the hull. Seems like most hulls can still accommodate a transducer while you are running. You just need to figure out what part of the hull is still in the water when you're on plane to position your transducer. You also need to consider where the transducer will not get too much water disturbance from the motor turbulence.

I don't know where that is for all hulls and boats but someone else might know or maybe a dealer that sells that hull?