My transducer went out on an old Signet depth-sounder about 15 years ago and I purchased a new one to replace it with. Signet told me to silicone the standard transducer to the inside of the hull and the next time we hauled it out, install it properly. I siliconed it down near the old one and it worked great. I never changed it.

I would think that if it's pointing relatively down there shouldn't be any problem. Why you have one I don't know.

Just my history with 'inside the hull' with a standard transducer.