Hello, I have a nice Catalina 27 that has an Apelco depth sounder model 360a. This sounder works fine and it's frequency is 200khz. The unit is mounted inside the cabin and is not visable by the tillerman. I wish to mount a new sounder to the cabin wall that CAN be read by the tillerman. Can someone please tell me if the same transducer can be used??? The current through hull transducer is Apelco model M78625. Thanks in advance John jat1127@hotmail.com