Fish finder installation

I am having an extremely difficult time getting to and reading the online instruction manual for the Eagle easyfish 240. I have the majority of the installation figured out, I only have one question that I am hoping somone can help with. The transducer is basically an oval shaped device with on end flattened, it also has a flat piece at the pointed end to attach the device outside of the craft on the transom. I am mounting the device to shoot through the hull. Which part of the transduce should be glued or gooped to the hull? The rounded bottom or the flattened end?

The rounded bottom. Hook it up and turn it on, then take it's 'pulse'. You should be able to feel where the sonar pings are coming from.  Epoxy that to the hull.

Another way to try it out before you goop it to the boat, is the sand bag and water method.  Place it in your hull, drop a few pounds of sandbag on it, add an inch of water in your hull, and presto-- portable finder.

You can substitute the water for gobs of vaseline as well...
(expecting comments on that one!)

Thank you for the info. As soon as it drops down to 110 F this evening, Ill get down to the garage and install it.

Don't epoxy it. Goop works fine and is easy to remove