You guys know I am a newbie so I ask a lot of questions. What happens if the water level drops after the ice is formed?
The reverse is also possible, after a fashion. You can have good ice, then get melting snow on top, or even rain, and you're wading through water while standing on the ice. I have punched holes to let the water drain off the ice....pretty wild watching a whirlpool effect take your line or float down.
Then, a cold spell will refreeze that slop, and the next time you go out your feet break through the weak junk before contacting the solid ice underneath.....VERY creepy, nerve wracking stuff.