I had a first generation Interphase forward looking sonar while I was cruising in the
South Pacific, and I did not find that it helped me that much when I really needed the help.
I was looking for something to use in restricted quarters near reef strewn waters, and I had the hope that it would keep me from making serious
mistakes striking
reefs and underwater obstruction.
In practice, I did not find it to be that helpful unless I was going really slowly forward. Otherwise I would be "overdriving my headlights" so to speak. By the time it showed up on the forward looking sonar, it was too late to help me.
I wanted to use it in relatively shallow
water, and I found it was least effective in shallow
water where it would help me the most. That was my experience.
I also did not want to spend my time looking at a sonar
screen. I would rather look at the water,
wind, and other navigational tools that did a good job of keeping me off
reefs. The way I navigated, I kept the
boat in safe water at safe speeds, and the sonar was not that much of a help. Other people probably have a different experience, and they may use the sonar in a different manner.
I also would not rely on it to find floating containers in front of the yacht.
I hope it works better for other people than it did for me.