Participants preparing to launch in the 1973 Bathtub Races in Mission Bay. The races were held at Crown Point Shores as part of activities celebrating San Diego's America's Finest City Week, August 24 - 31, 1973. The boats are small watercraft designed around bathtubs or close facsimiles. The rules restrict the engine to 8 horsepower and the weight to a minimum of 350 pounds including the driver.