I have done some homework on fishfinders and have heard you cant go wrong with the garmin 240. I have a Garmin gps and I love it. I plan to get a 240 but should I get the "blue" for trolling for salmon? The cone angles are much diferent between the 240 and the 240 blue. 40/10 for the blue (dual frequency) and 20 deg for the 240.

Toyman, I would recommend the 240 Blue over the 240, besides the dual frequency, the blue is a 500 watt RMS as opposed to 400 watt for the 240, the blue comes with speed and temp, just temp on the 240, and the screen on the blue is very sharp/crisp and easy to read (higher pixel count)
Another option if money is an issue is the 160 Blue, identical to the 240 Blue except for the pixel count. These are great fishfinders and there is nothing under 500 bucks that I can find that can compete with the Garmin's. Let me know if you have any other ?'s.