I got 2nd in a state wide science fair, for seeing how oil travels through different ground consistencies. It was meant to show where oil would travel in an oil spill. I set up a bunch of huge fish tanks, each filled with different kinds of ground material( sand, pebbles, ect.) Some I had layers of different material. I used food coloring to die the oil, so it was easier to see how the oil traveled(it worked really well). I won the school science fair and then got second at the state.
And if you want a ski related one, my friend did one where he studied the effect of ski wax on the environment. He spent months on it and actually ended up winning the connecticut state science fair.