In the US, people drive on the right side of the street. Similarly, when people in the US swim laps, it is customary to swim counterclockwise – on the right side of the swimming lane. But in countries where folks drive on the left (Aus, NZ, GB, UK, etc.), it is customary to swim laps clockwise – on the left side of the swimming lane. This adds an interesting element to international swim meets where it is customary to adopt the direction of swim according to the driving direction!