I'm waiting for a quote back from the Raymarine dealer on installing a Radar and C70 Chartplotter on our new to us Catalina 380. The radar and plotter came with the boat and are brand new in the box never installed. I have a quote of $350 to provide a crane and $10 a day to store the mast during the work. The rigger quoted a bit under $1800 and $80 parts to unstep and step the mast, plus run the cable to the bilge. My question is to those of you that have the radar dome mounted on the back of the boat on a post. I know this would be a great deal cheaper and I'm expecting the dealer quote to show this is true. He promised both quotes. Most of my sailing is local but we are planning cruises to Mexico. Do you notice a big difference in performance with the Radar on the back of the boat mounted lower of course. I understand the advantages of the higher mounting but wonder if the extra cost is worth it. Side Note: Please don't flame me on this. I have an in depth knowledge of radar operation. My question is if it is noticeable to owners that have a post mounted dome unit.