Please welcome Eyoyo Underwater Fishing Cameras.https://amzn.to/3siEgXn
unless there is local restrictions i think your good to go ....and i think the ashes are biodegradable.....
3 ft diameter fire for 3 hrs the other day on my pond melted 1/4 inch of ice. Heat rises boys and girls.
From experience a fire won’t melt more then 2-3 inches of ice usually.
My kids and I had a fire burning on 4" of ice a couple weeks back. They had it ripping all day long. I did specifically make my kids have it right next to shore over less than 2 fow over a known sandbar. Just to be cautious.We cleared our mess before we left and spudded through the ice in the middle of where the fire was. The boys were curious. I got the spud out to show them that we lost less than an inch of ice. We had bets going about how much ice we lost. I really wish I thought to bet a couple shoveling jobs.
too busy fishing to make a fire. if you ain't catching keep moving.