These pictures are not the greatest, I had to take them at night with the flash so it was hard to get a good shot. I might be able to take some before work tomorrow.
Here is the water tight threaded port.
http://share.ovi.com/original.aspx?c...080&size=large
Underneath I lifecaulked the peanut butter jar to the hull of the boat...
http://share.ovi.com/original.aspx?c...083&size=large
Then fill with water and drop in the transducer... The jar is just big enough or my transducer so it won't move around. If the jar were bigger I would have used plumbers putty on the sides hold in in place
http://share.ovi.com/original.aspx?c...082&size=large
And then put the top on the jar.. I cut a slot in the top but be carefull the plastic cracks very easily as mine did.
http://share.ovi.com/original.aspx?c...086&size=large
Then screw the port back in tightly and you have your transducer installed and the bait well still works.
Sorry for the poor pictures but I think you will get the idea.