installing new transducer

I want to install it on the front of a pontoon boat. If I attach it to the underneath of the floor, will it work correctly? There should be a air gap of about 18". I know some work "through the floor", but I think there was water touching the bottom. Another option is a trolling motor mount, but the under floor would be so easy if it would work.

I would think drilling holes and attaching to the pontoons would be a big no no.

Sonar doesn't work through air. That would be radar.

I think most people have a bracket on the back of one of the pontoons they mount it on. If they dont have one, they can have one welded on. The easiest answer is to mount on trolling motor.