Old transducer holes that leak.

[bassFISHIN]

So I have a slight problem. I just removed my old transducer and sealed the holes with a marine epoxy and then installed my new transducer in the same area. I just took the boat out and found that I was taking on some water. My question is what would be my best option to remedy this situation. Should I place a transducer transom plate over all of the old holes and seal around this plate to ensure that everything is sealed and watertight or is this not a good idea since I have my current transducer already installed and will create more holes of potential leakage. The old holes are now covered by the current transucer but the connection to the boat is not watertight due to the nature of the shape of the transducer mount. Any help would be greatly appreciated. Thanks.