@IN2DEEP - sounds to me like perhaps you and bodfish can give a small seminar to some of us willing to sit and listen. Question: is the amount of contained air in the shell fish a factor in reading as well as the density of the mass? After all these critters do release bubbles. Bubbles register on ff don't they? So along with your denser reading and bubbles would this be a some what logical approach to finding beds and mounds with a ff?
I am a little confused about this releasing of bubbles? Is this belching or just passing gas?
You can take a regular shovel, some old cut off jeans or bathing suit, some old shoes and head over to the water ski ramp on fiesta island (San Diego). You wade out from knee to waist level and you will feel the sea grass around your legs. You must walk slowly and quietly and not make a lot of vibration. You then sink the shovel into the grass wuickly with your one foot and bend it slightly forward to cut off the escape holes.
You lift with two hands and voila razor clams. I have done this on many ocassions to get the live bait the fish can't turn down.
You will need a few gallons of fresh water, a beach towel and a change of clothes when you are done. Also a large plastic bag to put your fishing clothes and shoes in. Everyone knows how fresh that water is on the back side of fiesta island.
You really want to do this during the summer months when the water is warm and also during a negative tide. Freash live razor clams catch fish.
Razor clams, worms and other sealife live where the sea grass is.
That's why the fish are in the grass. So, if you know your fishing in sea grass the clams are there.
Another way to find clam beds is to look for the little pillows and sheets.
Kind of sounds like the Beverly Hillbillies the Clambeds.