I am interested in installing a depth sounder in my swing keel 1987 Catalina 22. I would like to do a "shoot through hull installation" that does not require any holes in the hull.Some of the material that I have read about this says that to be effective, this type of installation only works on solid fiberglass hulls and that a hull with a sandwich construction is not suitable. This is defined as construction with a layer of fiberglass, then a layer of balsa or some other type of flotation material and then another layer of fiberglass.My questions are these:1. What type of hull construction is the Catalina 22?2. What might be the best place to mount the transducer? (I have heard before that it might be best in front of the keel as close to the center as possible.)3. Any other tips on how best to install such a transducer?Thanks in advance for your help.