Port side under the motor is where mine is on a twin 29 and in every bass boat I own or have owned they are always in the bilge area. They will stop working above appx 60 mph...they all stop working at high speeds.

Any luck on those pics? thx.

Ok so i took some pics myself today that show that my boat doesnt have a hand hole cover on the port side under the cabin step. Any thoughts? see pics...
http://s8.postimage.org/yr9h7dzlh/IMG_0767.jpg
http://s16.postimage.org/myevuvdt1/IMG_0768.jpg
http://s17.postimage.org/4plw5scz3/IMG_0771.jpg

Is yours a step hull?

That position under the step is way too far foward unless you only want it to work off plain, when mine airs out the transducer stops working.
Rich

Yes, Step is kinda under rear seat.

Under the cabin step is where everyone is saying to put it. Some say theirs is under the step from the factory.

No, not under the cabin step, but off to the side of it.... accessed thru a access cover that would be located in the stringer shown in your 2nd pic. As I stated earlier, transducer has to be 12" +/- off center for solid hull.

Have you ever removed that floor fill cap for a look? Just curious if you ever find water in there

Yeah, i was never going to mount the transducer on the very bottom keel. I know to mount a foot to the side. But I am showing that my boat has no access cover on the side of the step. I only showed the fill in the bottom of the floor so all could see what all I have. So I guess I'm screwed as far as mounting this thing?

My boat is in the shop but mine is mounted just to the right of the silver cover. What I would suggest you try is to get the boat in the water and place the tranduscer there to see if it work. You have to test it over the side of the boat then fill a bag with water and test it on the boat floor to see where the readings coincide. Most of the instructions you get with the transducers will tell you how to find the best mounting spot using that technique or one similar. Try that out and see waht you get.