Depth sounder for shallow water

I just recently got a quote from farsounder and the price is $75000 plus around 35000 for instalation. Quite pricey and out of most boaters range if you ask me.

 

without knowing what you are calling shallow waters, I got one from Bass Pro that had a 30 Degree angle to the cone and it does well in water less than 3' deep.
Dont know how deep it will go but so far its been good at 100' plus.
The little transducer points forward and looks out and down at the same time.
It has kept me from hitting a rock (well, not real hard anyway) but so far has not put any fish in the boat.

 

I used to work for a place that makes Ultrasonic sensors. Our range was limited (through air) to about 8 or 10". The speed at which the receive circuitry could be turned on and off was the problem. That was many years ago and I'm sure it has improved somewhat.

 

Make an acoustic "delay line."

Tom,

I know this thread is old, but I just read it and thought I'd add an odd thought: put the transducer from your current sounder in the end of a 3' pipe, pinging into the pipe. Then, at the other end of the pipe, make a fiber-glass "window" and fill the pipe completely with seawater. The water in the pipe should act like an acoustic delay line and allow you to sound the bottom right up to the window in the end of the pipe. So, if you mount this pipe/sounder vertically with the window end through a through-hull fitting of some sort you might just be in business for a depth sounder that works right up to the hull. If the pipe has a smooth inner surface there should also be very little signal loss. The purpose of the window in the pipe is only to keep the water in there, so you could also just use a vacuum, but then you would risk loosing your "delay line."

This is all theoretical and I haven't tried it, so . . .

BillyDoc