What are those blue lines on the snow?

Wondering about the blue lines on the ski and snowboard courses at the Winter Games? They are an important visual cue for the athletes.

The blue dye is put down by course workers, and usually it mimics the line of the course fairly well. The racers are not required to stay within the blue lines — just between the actual gates.

For skiers, the blue dye helps them to chart the path down the mountain and gauge the actual line they want to ski. Because of that, the dye is also often used as a reference point for coaches and racers to talk about when to start turns, which can sometimes be a few feet above the line.

“I sometimes wonder what they did before blue dye,” said Breezy Johnson, an American downhill skier, on Instagram after a competition in December 2021. “Hats off to those people,” she added.

Contrast is key in these winter sports. Serious accidents happen when highflying snowboarders and skiers lose their way in the air. It’s important for the athletes to be able to spot a safe landing.

That’s why the lip of the halfpipe is usually painted blue — a warning, like color on a curb.

But the dye wasn’t always there — nor was it blue. In the 1980s, pine boughs were used. Workers would stick green pine boughs measuring 6 to 8 inches along the sides of the course.