Without helmets. And often in just shoes — did you ever try walking in shoes on an ice skating rink? I guess it gets simpler with practice, still I wonder how many more % concussions and damaged wrists the cold weather caused
Natural ice on lakes is usually rougher, because it typically has snow on top that partially freezes on. Esp if there's frequent melt+refreeze.
There's the odd winter where you get ice smooth and snowless like a rink, but rare.
Used to walk around on ponds and lakes quite a bit as a kid.