Go somewhere else. I had my GPS installed by St. Clair Marina. Although I did not personally have to pay for the bill as the installation was booked for me as a gift by family, I would never have brought my boat to this marina for service. Not only was I way over charged, and I understand that marine technicians charge a lot per hour, the employees boxed my truck so I could not exit following completion of payment. When I approached the lady who works in the office she got very aggressive. This should have been a quick installation, with only a few screws, tie wraps, 2 wires on a small boat with all access points accessible. Being charged nearly a full days work is excessive. There are many other marinas in this small town. Go some where else.