I love this sight it lets me bounce my ideas off of other people. As for as the gravel on the ice is concerned I never thought of it floating off but I think it would warm up faster with the gravel on the top and settle to the bottom. It is a gamble. As far as the silt on the bottom I figure that some will sink into it but it might be another alternative of having a little different bottom for fish to spawn in.
Another idea my son in law used to drive a tri axle dump truck called the Rock Shooter. What it did was it had a conveyor belt on the back and was able to shoot rocks up to 70 feet. He told me of one time taking a load of sand to a lake and shooting it in to it so the guy could have a sandy bottom in it. Just another thought.
