While those are Bradley Fighting Vehicles, the "water obstacle" is actually what we call a wash rack. It's where we clean combat vehicles after training. The wash facility consists of a "bird bath", which is a pool filled with water that the vehicle is driven through to begin to loosen the dirt built up in the tracks and road wheels. After the bird bath, the vehicle is stopped at a hose set up where the operators use hoses and brushes to finish the cleaning.