I purchased the Eagle Fishmark 480 last October and I am very pleased with the way it performs. Of course, I have used nothing but Eagles since 1990. Visit the website www.eaglesonar.com. Download the free emulator software for the 480. This PC application simulates the actual sonar unit on your computer. You can run it with your mouse to press the virtual keys. By using this feature, I was able to master the unit before I ever got on the water.