Hi Fred... Stargazer ('79 hull #294) had a transducer mounted in the area that you're thinking about. IIRC, the proper trial procedure is to place the xducer in water over the spot you want to mount it. A tube of water siliconed to the spot and the xducer placed next to the hull will work better then the petro jelly. FWIW, do not use the silicon to affix the xducer to the hull...only epoxy. Also, IIRC, if you go to www.westmarine.com and check the fishfinder/depth finder pages you may also find a tech tip on mounting xducers Harvey/ Ga