When using GOOP for the transducer..?

In my old scupper pro (similar to the trident), I made a rubber dam from thick foam rubber, trimmed it to the shape of the transducer, glued it down, then filled with marine goop. Worked well and neat. Sorry no pics.

INSAYN, a couple of weeks ago I had problems getting the transducer level after topping off the puck and used a lot of water fiddling with it.  Last week I carried Gatorade instead of water, couldn't wade out far enough to reach clean, sand-free water and "borrowed" water from C_Run.  After that, I thought about what it would be like to be in bumpy water, scooted-up where I could reach the puck, with the Mod Pod wide open.  Two dumb days in a row got me to thinking about a way to mount the transducer that didn't depend on me bringing water (or enough water).  It was all operator technique, not a mechanical problem with the pucks.  (I didn't really think those were pictures of your work)

DK, thank you. That makes sense.  No pictures necessary.

INSAYN, a couple of weeks ago I had problems getting the transducer level after topping off the puck and used a lot of water fiddling with it.  Last week I carried Gatorade instead of water, couldn't wade out far enough to reach clean, sand-free water and "borrowed" water from C_Run.  After that, I thought about what it would be like to be in bumpy water, scooted-up where I could reach the puck, with the Mod Pod wide open.  Two dumb days in a row got me to thinking about a way to mount the transducer that didn't depend on me bringing water (or enough water).  It was all operator technique, not a mechanical problem with the pucks.  (I didn't really think those were pictures of your work)

DK, thank you. That makes sense.  No pictures necessary.

So, I'm still not understanding what your overall problem is.  You can use your Gatorade, dirty water (to a point), flat beer, piss, etc.. 
Just put your 'ducer in the puck and add the liquid of your choice enough to cover the ducer.  If you provided yourself a small groove in the foam along one side or end of the 'ducer, all you need to do is lightly burp it by lifting the 'ducer slightly up/down maybe 1/4" to let out any air bubbles that may be trapped.  They may escape on their own with the groove you provided the.   

You don't want your puck so tight that your 'ducer creates pressure below it as you push it in the foam. You also don't want it so loose that the 'ducer tries to escape with the slightest lean.

If your puck is at least 3" high, then your 'ducer will always have water in it even in rougher water than you would want to experience, and sporty surf launches.

Tinker, you got this man!

Well, I'm not telling what method I went with, but I will say that as I was applying GOOP from a brand new tube, the crimped end popped open and there's GOOP all over the darned place.   

"Leave well enough alone" I always say.  Starting now.