for sure not safe. we went out and the spud was not going thru and it was just creepy seeing thru the ice and all the pressure cracks then out of nowhere the spud hit and still didn't go thru but made a different sound so i hit it again in the same spot and the whole are just spider webbed. we backed up about 20 feet and drilled a hole and we were on about 2" of ice. we turned right around and left.