Check the 25.5 section in this site under Boat Information-Owner Modifications. There is a photo of where one owner placed his shoot thru the hull transducer. I had placed mine in the same location. Mine has worked very well placed there in a big ball of silicone. My bilge pump is located just aft of that location in the deepest part of the bilge. Hope this helps.
Go up to the top of this page and click on Boat Info then select boat model, then select Owner Modifications, There is a post with photo of the transducer towards the bottom. My bilge pump is in the deepest part of the bilge with the outlet hose running all the way back to the stern where one of the previous owners had installed it. It does not allow the bilge to get completely dry, just have to sponge that little bit out. I have only had one occasion where my bilge had any water in it so it hasn't been a big problem yet.