Quinte Fishing

Had the same problem with our Humming bird . The plug/plate is missing from your friends unit Dan.
Snarfy

I had the exact same problem too! it was so bad that water would make its way back into the boat and it didnt seem like small amounts either....

I raised mine up a couple inches and the problem went away (spray directed more outwards)

But i think it has something to do with the chord coming off the top of the transducer (same design as mine). so if you try fastening it tighter to the top of the transducer it might help??

those are the 2 things i did to eliminate the spray.

good luck let me know if it works!

Transducer placement is very tricky
it should be very slightly below boat for best results. if you raise it too high air bubbles from the boat bottom will cause interference with a good reading. also if too high you will not get any readings when boat is on plane or at a faster speed.
I had a lot of spray as well so I made a shield out of stainless steel.
It is screwed onto plastic board so no extra holes in transom.
My friend made one from a small steel dog dish cut in half


I know it is hanging a bit below so I am very carefull if beaching the boat to always let the back end of boat to float a bit
So far not a scratch on my transducer bottom. Wish I could say the same about my skeg!
Rob