I fiberglassed in a tube to the hull to mount my depth transducer up forward on the centerline. At this point the hull has a V.. The intent was to fill the tube with oil to fill the gap. It doesn't appear to be working all that well. It may be because I'm using an old low power sounder. Any ideas on a transducer that might work?. I like the location and a flush mount would have the transducer aimed out and angle.