How well did the 600L perform at 600ft? A 600 watt ducer has about a 40 degree beam on 50Khz. The FCV-600L was also a 350 watt machine. Both the FCV-620 and 627 have more power, 600 watts. But if you put a better transducer onboard you can increase the sounders performance even further. A better transducer will have a narrower beam width which will focus the sounders power into a smaller area producing better fish returns.